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 A343112 #12 Apr 06 2021 10:36:42 %S A343112 3,6,9,11,12,15,18,19,21,22,24,30,35,36,38,39,42,43,44,45,48,55,59,60, %T A343112 63,67,69,70,72,76,77,78,83,84,86,87,88,90,91,93,95,96,107,110,111, %U A343112 115,117,118,120,121,126,131,133,134,138,139,140,141,143,144 %N A343112 Numbers having exactly 1 divisor of the form 8*k + 3. %H A343112 Jianing Song, <a href="/A343112/b343112.txt">Table of n, a(n) for n = 1..10000</a> %e A343112 63 is a term since among the divisors of 63 (namely 1, 3, 7, 9, 21 and 63), the only divisor congruent to 3 modulo 8 is 3. %o A343112 (PARI) res(n,a,b) = sumdiv(n, d, (d%a) == b) %o A343112 isA343112(n) = (res(n,8,3) == 1) %Y A343112 Numbers having m divisors of the form 8*k + i: A343107 (m=1, i=1), A343108 (m=0, i=3), A343109 (m=0, i=5), A343110 (m=0, i=7), A343111 (m=2, i=1), this sequence (m=1, i=3), A343113 (m=1, i=5), A141164 (m=1, i=7). %Y A343112 Indices of 1 in A188170. %Y A343112 A007520 is a subsequence. %K A343112 nonn,easy %O A343112 1,1 %A A343112 _Jianing Song_, Apr 05 2021