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 A200049 #16 Oct 30 2018 10:31:02 %S A200049 2,3,5,7,9,12,14,16,20,21,27,29,30,34,37,44,45,48,52,53,58,61,65,71, %T A200049 75,76,78,79,84,93,97,100,101,109,111,115,119,122,128,132,133,142,144, %U A200049 146,147,157,165,169,170,172,178,180,188,193,198,202,203,207,211,213,221,231,233,234,238,251,254,261,263,267,271 %N A200049 Positions of squares of odd primes among odd powerful numbers A062739. %H A200049 Zak Seidov, <a href="/A200049/b200049.txt">Table of n, a(n) for n = 1..1000</a> %F A200049 A062739(a(n)) = (A000040(n+1))^2. %o A200049 (PARI) lista(nn) = select(x->(issquare(x) && isprime(sqrtint(x))), select(x->(ispowerful(x) && (x % 2)), vector(nn, k, k)), 1); \\ _Michel Marcus_, Jun 18 2017 %Y A200049 Cf. A000040, A062739. %K A200049 nonn %O A200049 1,1 %A A200049 _Zak Seidov_, Nov 13 2011