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 A378489 #14 Jul 09 2025 05:07:28 %S A378489 4,9,16,24,25,40,49,54,56,60,81,84,88,90,96,104,121,126,132,135,136, %T A378489 140,150,152,156,160,169,184,189,198,204,220,224,228,232,234,240,248, %U A378489 250,256,260,276,289,294,296,297,306,308,315,328,336,340,342,344,348,350 %N A378489 Intersection of A000028 and A028260. %C A378489 First differs from A066427 at n = 11, where A066427(11) = 72 is missing from this sequence. %H A378489 Paolo Xausa, <a href="/A378489/b378489.txt">Table of n, a(n) for n = 1..10000</a> %t A378489 A000028Q[k_] := k > 1 && OddQ[Count[IntegerDigits[FactorInteger[k][[All, 2]], 2], 1, 2]]; %t A378489 A028260Q[k_] := EvenQ[PrimeOmega[k]]; %t A378489 Select[Range[500], A000028Q[#] && A028260Q[#] &] %Y A378489 Cf. A000028, A028260, A066427, A378494. %K A378489 nonn %O A378489 1,1 %A A378489 _Paolo Xausa_, Nov 28 2024, following a suggestion from _Peter Munn_