This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A376354 #7 Sep 22 2024 18:07:25
%S A376354 3,6,9,10,13,15,18,21,24,27,28,31,34,36,39,42,45,48,51,54,55,58,61,64,
%T A376354 65,66,69,72,75,76,78,81,84,87,88,91,94,97,100,101,104,105,108,111,
%U A376354 114,115,118,120,123,126,129,130,133,135,136,139,142,145,146,149
%N A376354 Numbers that end in 0 when written in base of triangular numbers (cf. A000462).
%C A376354 Every positive integer is in exactly one of the following sequences: this sequence, A376355, or A376356.
%C A376354 Conjecture: {a(n+1) - a(n) : n >= 1} = {1, 2, 3}. (See related conjectures at A376355 and A376356.)
%t A376354 a[n_, poly_] := FromDigits[FoldList[{Mod[#[[1]], #2], Quotient[#[[1]], #2]} &, {n, 0}, Reverse[Map[(poly - 2) # (# - 1)/2 + # &, Range[Floor[Sqrt[2 n]]]]]][[All, 2]]]
%t A376354 t3 = Map[a[#, 3] &, Range[200]]; (* A000462 *)
%t A376354 m = Mod[t3, 10]
%t A376354 Table[Flatten[Position[m, r]], {r, 0, 2}]
%t A376354 p0 = Flatten[Position[m, 0]] (* this sequence *)
%t A376354 p1 = Flatten[Position[m, 1]] (* A376355 *)
%t A376354 p2 = Flatten[Position[m, 2]] (* A376356 *)
%t A376354 (* _Peter J. C. Moses_, Sep 20 2024 *)
%Y A376354 Cf. A000462, A376355, A376356, A376357.
%K A376354 nonn,base
%O A376354 1,1
%A A376354 _Clark Kimberling_, Sep 22 2024