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 A382696 #10 Apr 12 2025 11:58:27
%S A382696 276,456,1266,1626,2176,2976,3516,5406,6126,8556,9456,12426,13506,
%T A382696 17016,18276,22326,23766,28356,29976,35106,36906,39376,42576,44556,
%U A382696 50766,52926,59676,62016,69306,71826,79656,82356,89776,90726,93606,94576,102516,105576,115026,118266,128256,131676,142206,145806
%N A382696 Centered pentagonal numbers that are abundant.
%C A382696 The sequence is infinite, e.g. A005891(n) is a term when 1 < n == 1 or 10 (mod 12). - _Robert Israel_, Apr 06 2025
%e A382696 276 = 2^2*3*23 is a term since it is a centered pentagonal number and less than the sum of its proper divisors (1+2+3+4+6+12+23+46+69+92+138=396).
%e A382696 456 = 2^3*3*19 is a term since it is a centered pentagonal number and less than the sum of its proper divisors (1+2+3+4+6+8+12+19+24+38+ 57+ 76+114+152+228=744).
%p A382696 select(t -> numtheory:-sigma(t) > 2*t, [seq((5*n^2+5*n+2)/2, n=1..500)]); # _Robert Israel_, Apr 06 2025
%t A382696 Select[Table[(5*n^2 + 5*n + 2)/2, {n, 1, 250}], DivisorSigma[-1, #] > 2 &] (* _Amiram Eldar_, Apr 03 2025 *)
%Y A382696 Intersection of A005891 and A005101.
%Y A382696 Cf. A379264.
%K A382696 nonn
%O A382696 1,1
%A A382696 _Massimo Kofler_, Apr 03 2025