Number of ON cells in 3-D cellular automaton described in Comments, after n generations.

Terms

a(0) =1a(1) =26a(2) =26a(3) =124a(4) =26a(5) =676a(6) =124a(7) =1400a(8) =26a(9) =676a(10) =676a(11) =3224a(12) =124a(13) =3224a(14) =1400a(15) =10000a(16) =26a(17) =676a(18) =676a(19) =3224a(20) =676a(21) =17576a(22) =3224a(23) =36400a(24) =124a(25) =3224a(26) =3224a(27) =15376a(28) =1400a(29) =36400