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 A269360 #7 Mar 15 2016 00:16:08 %S A269360 2,4,6,10,8,16,12,22,26,28,14,34,18,40,36,46,20,52,24,58,56,64,30,70, %T A269360 50,76,66,82,32,88,38,94,86,100,78,106,42,112,96,118,44,124,48,130, %U A269360 116,136,54,142,122,148,126,154,60,160,92,166,146,172,62,178,68,184,156,190,120,196,72,202,176,208,74,214,80,220,186,226,144 %N A269360 Permutation of even numbers: a(n) = 1 + A250469(n). %H A269360 Antti Karttunen, <a href="/A269360/b269360.txt">Table of n, a(n) for n = 1..16384</a> %F A269360 a(n) = 1 + A250469(n). %F A269360 a(n) = 2 + A253886(n-1). %t A269360 (* b = A250469 *) b[1] = 1; b[n_] := If[PrimeQ[n], NextPrime[n], m1 = p1 = FactorInteger[n][[1, 1]]; For[ k1 = 1, m1 <= n, m1 += p1; If[m1 == n, Break[]]; If[ FactorInteger[m1][[1, 1]] == p1, k1++]]; m2 = p2 = NextPrime[p1]; For[k2 = 1, True, m2 += p2, If[ FactorInteger[m2][[1, 1]] == p2, k2++]; If[k1+2 == k2, Return[m2]]]]; %t A269360 a[n_] := b[n] + 1; %t A269360 Array[a, 100] (* _Jean-François Alcover_, Mar 14 2016 *) %o A269360 (Scheme) (define (A269360 n) (+ 1 (A250469 n))) %Y A269360 Cf. A253886, A250469, A243501. %Y A269360 Cf. also A269863, A269864. %K A269360 nonn %O A269360 1,1 %A A269360 _Antti Karttunen_, Mar 13 2016