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 A352090 #11 Mar 12 2022 12:13:01
%S A352090 1,6,7,12,13,20,26,27,39,68,75,80,81,87,115,128,135,149,176,184,185,
%T A352090 195,204,215,224,230,236,243,264,278,284,291,344,364,399,447,506,507,
%U A352090 519,548,555,560,575,595,615,635,656,664,665,684,704,725,744,777,804,824
%N A352090 Numbers k such that k and k+1 are both tribonacci-Niven numbers (A352089).
%C A352090 Numbers k such that A278043(k) | k and A278043(k+1) | k+1.
%C A352090 The odd tribonacci numbers, A000073(A042964(m)), are all terms.
%H A352090 Amiram Eldar, <a href="/A352090/b352090.txt">Table of n, a(n) for n = 1..10000</a>
%e A352090 6 is a term since 6 and 7 are both tribonacci-Niven numbers: the minimal tribonacci representation of 6, A278038(6) = 110, has 2 1's and 6 is divisible by 2, and the minimal tribonacci representation of 7, A278038(7) = 1000, has one 1 and 7 is divisible by 1.
%t A352090 t[1] = 1; t[2] = 2; t[3] = 4; t[n_] := t[n] = t[n - 1] + t[n - 2] + t[n - 3]; q[n_] := Module[{s = {}, m = n, k}, While[m > 0, k = 1; While[t[k] <= m, k++]; k--; AppendTo[s, k]; m -= t[k]; k = 1]; Divisible[n, DigitCount[Total[2^(s - 1)], 2, 1]]]; Select[Range[1000], q[#] && q[# + 1] &]
%Y A352090 Cf. A000073, A042964, A278038, A278043.
%Y A352090 Subsequence of A352089.
%Y A352090 Subsequences: A352091, A352092.
%Y A352090 Similar sequences: A330927, A328205, A328209, A328213, A330931, A331086, A333427, A334309, A331820, A342427, A344342, A351715, A351720.
%K A352090 nonn,base
%O A352090 1,2
%A A352090 _Amiram Eldar_, Mar 04 2022