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 A359544 #5 Jan 05 2023 10:54:17 %S A359544 1,2,3,5,6,7,9,10,11,13,14,17,18,19,21,22,23,25,29,31,33,34,37,38,41, %T A359544 42,43,46,47,49,53,57,58,59,61,62,65,66,67,71,73,77,79,82,83,85,89,93, %U A359544 94,97,98,101,103,107,109,113,114,118,121,127,129,131,137,139,142,145,149,151,154,157,161,163,166 %N A359544 Numbers k such that all their divisors (including k itself) are in A099308, i.e., reach eventually zero when iterated with the arithmetic derivative. %e A359544 30 = 2*3*5, although it is in A099308, is not included here because its divisor 15 is not in A099308. %o A359544 (PARI) isA359544(n) = A359543(n); %Y A359544 Positions of 0's in A359542. %Y A359544 Setwise difference A099308 \ A359545. %Y A359544 Cf. A359543 (characteristic function). %K A359544 nonn %O A359544 1,2 %A A359544 _Antti Karttunen_, Jan 05 2023