27623 is a member of OEIS A036301: numbers whose sum of even digits and sum of odd digits are equal. See blog post titled Odds and Evens: Statistics. How many "captives" are captured by the "attractor" 27623? The answer is 3 and the captives are 27555, 27575 and 27597. Permalink

The sequence can be generated as follows (permalink):

INPUT

L=[]

for n in [1..40000]:

  D=n.digits()

  sumE,sumO=0,0

  for d in D:

    if d%2==1:

      sumO+=d

    if d%2==0:

      sumE+=d

  if sumE==sumO:

    L.append(n)

print(L)

print(len(L))

OUTPUT (only numbers from 27623 to 40000 listed)

[ ... 27623, 27632, 27645, 27654, 27667, 27676, 27689, 27698, 27748, 27766, 27784, 27803, 27825, 27830, 27847, 27852, 27869, 27874, 27896, 27968, 27986, 28019, 28037, 28055, 28073, 28091, 28109, 28190, 28239, 28257, 28275, 28293, 28307, 28329, 28370, 28392, 28459, 28477, 28495, 28505, 28527, 28549, 28550, 28572, 28594, 28679, 28697, 28703, 28725, 28730, 28747, 28752, 28769, 28774, 28796, 28899, 28901, 28910, 28923, 28932, 28945, 28954, 28967, 28976, 28989, 28998, 29018, 29081, 29108, 29126, 29144, 29162, 29180, 29216, 29238, 29261, 29283, 29328, 29346, 29364, 29382, 29414, 29436, 29441, 29458, 29463, 29485, 29548, 29566, 29584, 29612, 29621, 29634, 29643, 29656, 29665, 29678, 29687, 29768, 29786, 29801, 29810, 29823, 29832, 29845, 29854, 29867, 29876, 29889, 29898, 29988, 30014, 30036, 30041, 30058, 30063, 30085, 30104, 30122, 30140, 30212, 30221, 30234, 30243, 30256, 30265, 30278, 30287, 30306, 30324, 30342, 30360, 30401, 30410, 30423, 30432, 30445, 30454, 30467, 30476, 30489, 30498, 30508, 30526, 30544, 30562, 30580, 30603, 30625, 30630, 30647, 30652, 30669, 30674, 30696, 30728, 30746, 30764, 30782, 30805, 30827, 30849, 30850, 30872, 30894, 30948, 30966, 30984, 31004, 31022, 31040, 31116, 31138, 31161, 31183, 31202, 31220, 31318, 31381, 31400, 31611, 31813, 31831, 32012, 32021, 32034, 32043, 32056, 32065, 32078, 32087, 32102, 32120, 32201, 32210, 32223, 32232, 32245, 32254, 32267, 32276, 32289, 32298, 32304, 32322, 32340, 32403, 32425, 32430, 32447, 32452, 32469, 32474, 32496, 32506, 32524, 32542, 32560, 32605, 32627, 32649, 32650, 32672, 32694, 32708, 32726, 32744, 32762, 32780, 32807, 32829, 32870, 32892, 32928, 32946, 32964, 32982, 33006, 33024, 33042, 33060, 33118, 33181, 33204, 33222, 33240, 33402, 33420, 33600, 33811, 34001, 34010, 34023, 34032, 34045, 34054, 34067, 34076, 34089, 34098, 34100, 34203, 34225, 34230, 34247, 34252, 34269, 34274, 34296, 34302, 34320, 34405, 34427, 34449, 34450, 34472, 34494, 34504, 34522, 34540, 34607, 34629, 34670, 34692, 34706, 34724, 34742, 34760, 34809, 34890, 34908, 34926, 34944, 34962, 34980, 35008, 35026, 35044, 35062, 35080, 35206, 35224, 35242, 35260, 35404, 35422, 35440, 35602, 35620, 35800, 36003, 36025, 36030, 36047, 36052, 36069, 36074, 36096, 36111, 36205, 36227, 36249, 36250, 36272, 36294, 36300, 36407, 36429, 36470, 36492, 36502, 36520, 36609, 36690, 36704, 36722, 36740, 36906, 36924, 36942, 36960, 37028, 37046, 37064, 37082, 37208, 37226, 37244, 37262, 37280, 37406, 37424, 37442, 37460, 37604, 37622, 37640, 37802, 37820, 38005, 38027, 38049, 38050, 38072, 38094, 38113, 38131, 38207, 38229, 38270, 38292, 38311, 38409, 38490, 38500, 38702, 38720, 38904, 38922, 38940, 39048, 39066, 39084, 39228, 39246, 39264, 39282, 39408, 39426, 39444, 39462, 39480, 39606, 39624, 39642, 39660, 39804, 39822, 39840]

27623 is a cyclic and Duffinian number.

27623 can be rendered as a digit equation as follows:

-2 + 7 = 6 + 2 - 3