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 A257245 #12 Apr 19 2015 22:24:53 %S A257245 2,3,3,3,3,5,5,3,3,5,7,7,7,3,19,7,5,5,7,5,19,11,13,13,23,13,11,11,61, %T A257245 31,13,19,43,13,7,5,61,31,23,127,7,151,19,181,13,43,31,233,13,13,7,11, %U A257245 19,31,59,31,31,163,41,41,113,11,19,19,409,41,41,41,19,41,113,29,167,13,17,11,179,19,19,13,5 %N A257245 Odd bisection of A257244: a(n) = A257244(2n - 1). %H A257245 Antti Karttunen, <a href="/A257245/b257245.txt">Table of n, a(n) for n = 1..2048</a> %F A257245 a(n) = A257244(2n - 1). %F A257245 a(n) = A006530(A256393(2n - 1)). [Equally, the largest prime factor of A256393(2n-1).] %F A257245 Other identities and observations: %F A257245 For all n >= 1, a(n) >= A257246(n). %o A257245 (Scheme, alternative definitions) %o A257245 (define (A257245 n) (A257244 (+ n n -1))) %o A257245 (define (A257245 n) (A006530 (A256393 (+ n n -1)))) %Y A257245 Cf. A006530, A256393, A257244. %Y A257245 Cf. also A257246 (the other bisection), A257247 (gives the positions where both bisections have the same value). %K A257245 nonn %O A257245 1,1 %A A257245 _Antti Karttunen_, Apr 19 2015