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 A082902 #14 Oct 01 2023 02:40:03 %S A082902 1,1,2,1,2,2,2,1,1,2,2,2,2,2,4,1,2,1,2,2,4,2,2,2,1,2,4,2,2,4,2,1,4,2, %T A082902 4,1,2,2,4,2,2,4,2,2,2,2,2,2,1,1,4,2,2,4,4,2,4,2,2,4,2,2,2,1,4,4,2,2, %U A082902 4,4,2,1,2,2,2,2,4,4,2,2,1,2,2,4,4,2,4,2,2,2,4,2,4,2,4,2,2,1,2,1,2,4,2,2,8 %N A082902 a(n) = gcd(2^n, sigma(2,n)) = gcd(A000079(n), A001157(n)). %H A082902 Antti Karttunen, <a href="/A082902/b082902.txt">Table of n, a(n) for n = 1..65537</a> %F A082902 a(n) = A006519(A001157(n)). - _Antti Karttunen_, Sep 27 2018 %F A082902 Multiplicative with a(2^e) = 1, and a(p^e) = A006519(e+1) for an odd prime p. - _Amiram Eldar_, Oct 01 2023 %t A082902 a[n_] := 2^IntegerExponent[DivisorSigma[2, n], 2]; Array[a, 100] (* _Amiram Eldar_, Oct 01 2023 *) %o A082902 (PARI) A082902(n) = gcd(2^n, sigma(n, 2)); \\ _Antti Karttunen_, Sep 27 2018 %Y A082902 Cf. A000079, A001157, A006519. %K A082902 nonn,mult %O A082902 1,3 %A A082902 _Labos Elemer_, Apr 22 2003