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 A342457 #11 Mar 18 2021 22:57:00 %S A342457 2,2,2,4,2,4,6,6,2,4,64,16,324,36,10,36,2,4,64,16,2304,96,486,24,7290, %T A342457 104976,21600,1296,1708593750000,100,93750,10,2,4,64,16,144,6,216,6, %U A342457 172186884,7776,2160,216,216000000,236196,10497600,54,10935000000000,53144100,1476225000000,7290,122500000000,10935000,140,360 %N A342457 Terms of A342456 prime-shifted so far towards lower primes that they become even: a(n) = 2*A246277(A342456(n)). %C A342457 These terms have the same prime signature as the corresponding terms in A342456, thus applying omega and bigomega to these gives the same derived sequences A342461 and A342462. %H A342457 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %H A342457 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a> %F A342457 a(n) = 2*A246277(A342456(n)) = 2*A329038(A329886(n)). %o A342457 (PARI) %o A342457 A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1,1])-1); for (i=1, #f~, f[i,1] = prime(primepi(f[i,1])-k)); factorback(f)/2); %o A342457 A342457(n) = 2*A246277(A342456(n)); \\ Uses also code from A342456. %Y A342457 Cf. A246277, A276086, A283980, A329038, A329886, A342456, A342461 [= A001221(a(n))], A342462 [= A001222(a(n))], A342464 [= A051903(a(n))]. %K A342457 nonn %O A342457 0,1 %A A342457 _Antti Karttunen_, Mar 15 2021