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 A025715 #48 Jul 06 2025 13:14:47
%S A025715 1,3,6,10,15,21,28,36,45,56,68,81,95,110,126,143,161,180,201,223,246,
%T A025715 270,295,321,348,376,405,436,468,501,535,570,606,643,681,720,761,803,
%U A025715 846,890,935,981,1028,1076,1125,1176,1228,1281,1335,1390,1446,1503,1561,1621
%N A025715 Index of 6^n in A025622 (numbers of form 5^i*6^j).
%C A025715 Positions of zeros in A025651. - _R. J. Mathar_, Jul 06 2025
%H A025715 David A. Corneth, <a href="/A025715/b025715.txt">Table of n, a(n) for n = 0..9999</a> (First 500 terms from Giovanni Resta)
%H A025715 W. Kuszmaul, <a href="http://arxiv.org/abs/1509.08216">Fast Algorithms for Finding Pattern Avoiders and Counting Pattern Occurrences in Permutations</a>, arXiv preprint arXiv:1509.08216 [cs.DM], 2015.
%F A025715 a(n) >= binomial(n+2, 2). - _David A. Corneth_, Jul 20 2017
%o A025715 (PARI) lista(nn) = {v = []; for (n=0, nn, for (m = 0, nn, v = vecsort(concat(v, 5^n*6^m),,8););); n=0; for (k=1, #v, vk = v[k]; if ((valuation(vk, 6)==n) && (valuation(vk, 5) == 0), if (vk > 5^(nn+1), return(), print1(k, ", "); n++);););} \\ _Michel Marcus_, Sep 28 2015
%Y A025715 Cf. A025622, A025707.
%K A025715 nonn,easy
%O A025715 0,2
%A A025715 _David W. Wilson_
%E A025715 Offset set to 0 by _Michel Marcus_, Sep 27 2015