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 A359821 #8 Jan 14 2023 17:19:20 %S A359821 1,2,6,9,10,14,15,18,21,22,25,26,30,33,34,35,38,39,42,46,49,50,51,54, %T A359821 55,57,58,62,65,66,69,70,74,77,78,81,82,85,86,87,90,91,93,94,95,98, %U A359821 102,106,110,111,114,115,118,119,121,122,123,126,129,130,133,134,135,138,141,142,143,145,146,150,154 %N A359821 Numbers k whose arithmetic derivative, A003415(k), has the opposite parity to k. %o A359821 (PARI) isA359821(n) = A359820(n); %Y A359821 Cf. A003415, A359820 (characteristic function), A359822 (complement). %Y A359821 Positions of odd terms in A129283 and in A168036. %K A359821 nonn,easy %O A359821 1,2 %A A359821 _Antti Karttunen_, Jan 14 2023 %E A359821 Name edited by _Peter Munn_, Jan 14 2023