%I #25 Apr 19 2024 01:59:53
%S 1,2,12,121,212,1212,12121,21212,121212,1212121,2121212,12121212,
%T 121212121,212121212,1212121212,12121212121,21212121212,121212121212,
%U 1212121212121,2121212121212,12121212121212,121212121212121,212121212121212,1212121212121212,12121212121212121
%N Two-bell analog of A028355.
%C Consider the infinite digits: 121212... . We can break this into a sequence of integers such that the sum of digits in the n-th value is n. - _Seiichi Manyama_, Oct 31 2018
%H Seiichi Manyama, <a href="/A028359/b028359.txt">Table of n, a(n) for n = 1..1500</a>
%F Conjectures from _Chai Wah Wu_, Apr 18 2024: (Start)
%F a(n) = 101*a(n-3) - 100*a(n-6) for n > 6.
%F G.f.: x*(10*x^4 + 20*x^3 + 12*x^2 + 2*x + 1)/(100*x^6 - 101*x^3 + 1). (End)
%Y Cf. A000034, A028355.
%K nonn,base
%O 1,2
%A _N. J. A. Sloane_
%E More terms from _Seiichi Manyama_, Oct 31 2018