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 A351095 #7 Feb 03 2022 16:45:10 %S A351095 35,57,65,93,145,177,205,209,217,219,237,289,303,305,323,377,393,413, %T A351095 415,427,453,473,485,497,515,517,529,533,537,553,597,629,681,697,699, %U A351095 713,749,781,785,793,817,835,849,869,895,917,933,965,989,1037,1057,1059,1077,1081,1133,1137,1145,1149,1159,1169,1227,1243 %N A351095 Semiprimes that are not the arithmetic derivative (A003415) of any integer. %C A351095 17^2 = 289 and 23^2 = 529 are the first squares present. %o A351095 (PARI) %o A351095 A002620(n) = ((n^2)>>2); %o A351095 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A351095 isA351095(n) = if(2!=bigomega(n), 0, for(k=1,A002620(n),if(A003415(k)==n,return(0))); (1)); %Y A351095 Complement of A351096 in A001358. Subsequence of A098700 and of A189554. %Y A351095 Cf. A003415, A189483. %K A351095 nonn %O A351095 1,1 %A A351095 _Antti Karttunen_, Feb 03 2022