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 A352508 #9 Apr 01 2022 11:38:11
%S A352508 1,2,4,5,6,9,10,12,14,16,18,21,24,28,30,32,33,40,42,44,45,48,55,56,57,
%T A352508 60,65,72,78,80,84,88,95,100,105,112,126,128,130,132,134,135,138,140,
%U A352508 144,145,146,147,152,155,156,168,170,174,180,184,185,195,210,216
%N A352508 Catalan-Niven numbers: numbers that are divisible by the sum of the digits in their representation in terms of the Catalan numbers (A014418).
%C A352508 Numbers k such that A014420(k) | k.
%C A352508 All the Catalan numbers (A000108) are terms.
%C A352508 If k is an odd Catalan number (A038003), then k+1 is a term.
%H A352508 Amiram Eldar, <a href="/A352508/b352508.txt">Table of n, a(n) for n = 1..10000</a>
%e A352508 4 is a term since its Catalan representation, A014418(4) = 20, has the sum of digits A014420(4) = 2 + 0 = 2 and 4 is divisible by 2.
%e A352508 9 is a term since its Catalan representation, A014418(9) = 120, has the sum of digits A014420(9) = 1 + 2 + 0 = 3 and 9 is divisible by 3.
%t A352508 c[n_] := c[n] = CatalanNumber[n]; q[n_] := Module[{s = {}, m = n, i}, While[m > 0, i = 1; While[c[i] <= m, i++]; i--; m -= c[i]; AppendTo[s, i]]; Divisible[n, Plus @@ IntegerDigits[Total[4^(s - 1)], 4]]]; Select[Range[216], q]
%Y A352508 Cf. A014418, A014420.
%Y A352508 Subsequences: A000108, A038003, A352509, A352510, A352511.
%Y A352508 Similar sequences: A005349, A049445, A064150, A064438, A064481, A118363, A328208, A328212, A331085, A333426, A342726, A334308, A331728, A342426, A344341, A351714, A351719, A352089, A352107, A352320, A352342.
%K A352508 nonn,base
%O A352508 1,2
%A A352508 _Amiram Eldar_, Mar 19 2022