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 A278781 #16 May 25 2024 09:14:09 %S A278781 15,106,122,131,136,253,295,327,339,383,412,449,465,517,520,551,580, %T A278781 581,599,602,632,648,669,677,776,806,815,838,904,927,1071,1137,1166, %U A278781 1174,1199,1263,1275,1298,1325,1375,1399,1404,1425,1554,1564,1641,1684,1688 %N A278781 Numbers m such that A000041(m) is of the form 2^4 * k for odd k. %C A278781 Numbers m such that A278478(m) = 4. %C A278781 Also numbers m such that A000041(m) has four times as many even divisors as odd divisors. %H A278781 Colin Barker, <a href="/A278781/b278781.txt">Table of n, a(n) for n = 1..600</a> %F A278781 A000041(a(n)) = A278198(n). %t A278781 Select[Range[1700], IntegerExponent[PartitionsP[#], 2] == 4 &] (* _Amiram Eldar_, May 25 2024 *) %o A278781 (PARI) isok(n) = valuation(numbpart(n), 2)==4; %o A278781 select(n->isok(n), vector(2000, n, n)) %Y A278781 Cf. A000041, A278198, A278779, A278780, A278782, A278783, A278784. %Y A278781 Positions of 4's in A278478. %K A278781 nonn %O A278781 1,1 %A A278781 _Colin Barker_, Nov 28 2016