Here is an article regarding the 3D Moore neighborhoood, regarding OEIS seq\ uences A246031, that is the run-length transform of A246032 Note: With a few more seconds, the generating function can be rigorously pro\ ved, and it has been. 2 2 2 2 2 2 2 2 2 2 2 2 On the sequence, (x y z + x y z + x y z + x y z + x y + x y z 2 2 2 2 2 2 2 2 2 2 2 + x z + x y z + x y z + y z + x y + x z + x y + x z + y z 2 2 2 2 n + y z + x + x y + x z + y + y z + z + x + y + z + 1) , modulo , 2, evaluated at , {x = 1, y = 1, z = 1} By Shalosh B. Ekhad The first, 41, terms staring at n=0 are [1, 26, 26, 124, 26, 676, 124, 1400, 26, 676, 676, 3224, 124, 3224, 1400, 10000 , 26, 676, 676, 3224, 676, 17576, 3224, 36400, 124, 3224, 3224, 15376, 1400, 36400, 10000, 89504, 26, 676, 676, 3224, 676, 17576, 3224, 36400, 676] Just for kicks, the googol-th term of our sequence is 1578967581759084531284396199476117921426130608061678733368758435553827370086907\ 27998362636561268552499200000000000000000000 i The first , 40, terms of the sparse subsequence at the, 2 - 1, places are [1, 26, 124, 1400, 10000, 89504, 707008, 5924480, 47900416, 393069824, 3189761536, 25963397888, 210468531712, 1706090904320, 13803141607936, 111595408530176, 901164713600512, 7271581998320384, 58625571435837952, 472335388734974720, 3803021424555945472, 30602681612309510912, 246127842107210007040, 1978595589150751521536, 15898858268788381120000, 127704325127232135637760, 1025394869559837785950720, 8230701044550794151840512, 66047322008709487046884864, 529855967717721245086571264, 4249668115993276902348001792, 34076594378530894954320190208, 273193179174866658847566956032, 2189796492128874867606400944896, 17549506807905482713515906898432, 140624087523724691586571442432768, 1126662821325008405515311862025728, 9025534595958919357012676106156800, 72293864503507265936363789228319232, 579007059512763889097172865755036416, 4636862091411194346267051889244902912] Using the found enumerative automaton with, 110, states, that we omit, it follows that the Guessed (but absolutely certain!) rational generating function for that \ sparse subsequence is 10 9 8 7 6 5 - (737280 t - 260096 t - 887296 t + 428928 t + 61312 t - 59432 t 4 3 2 / 10 + 5420 t + 1718 t - 317 t + 6 t + 1) / ((8 t - 1) (110592 t / 9 8 7 6 5 4 3 - 29696 t - 140032 t + 52992 t + 22576 t - 9920 t - 856 t + 608 t 2 - 17 t - 12 t + 1)) and in Maple notation -(737280*t^10-260096*t^9-887296*t^8+428928*t^7+61312*t^6-59432*t^5+5420*t^4+ 1718*t^3-317*t^2+6*t+1)/(8*t-1)/(110592*t^10-29696*t^9-140032*t^8+52992*t^7+ 22576*t^6-9920*t^5-856*t^4+608*t^3-17*t^2-12*t+1) This ends this article, that took, 0.148, seconds.