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A376359 Positions of numbers in A007961 that end in 2.

%I A376359 #7 Sep 28 2024 12:59:12
%S A376359 2,6,11,15,18,22,27,31,38,42,47,51,55,60,66,70,75,79,83,87,92,96,99,
%T A376359 102,106,111,115,118,123,127,132,136,139,143,146,150,155,159,162,166,
%U A376359 171,175,180,184,187,191,198,202,207,211,214,218,223,227,231,236,240
%N A376359 Positions of numbers in A007961 that end in 2.
%C A376359 Every positive integer is in exactly one of these sequences: A376357, A376358, this sequence, or A376360.
%C A376359 Conjecture: {a(n+1) - a(n) : n >= 1} = {3,4,5,6,7,8,9,10}. (See related conjectures at A376357, A376358, and A376360.)
%t A376359 a[n_, poly_] := FromDigits[FoldList[{Mod[#[[1]], #2], Quotient[#[[1]], #2]} &, {n, 0}, Reverse[Map[(poly - 2)  #  (# - 1)/2 + # &,
%t A376359 Range[Floor[Sqrt[2  n]]]]]][[All, 2]]]
%t A376359 t4 = Map[a[#, 4] &, Range[200]];  (* A007961 *)
%t A376359 m = Mod[t4, 10];
%t A376359 Table[Flatten[Position[m, r]], {r, 0, 2}]
%t A376359 p0 = Flatten[Position[m, 0]]  (* A376357 *)
%t A376359 p1 = Flatten[Position[m, 1]]  (* A376359 *)
%t A376359 p2 = Flatten[Position[m, 2]]  (* this sequence *)
%t A376359 p3 = Flatten[Position[m, 3]]  (* A376360 *)
%t A376359 (* _Peter J. C. Moses_, Sep 20 2024 *)
%Y A376359 Cf. A007961, A376354, A376357, A376358, A376360.
%K A376359 nonn,base
%O A376359 1,1
%A A376359 _Clark Kimberling_, Sep 25 2024