A364949 a(n) = gcd(A348717(n), A348717(A163511(n))).

1, 2, 2, 4, 2, 6, 2, 8, 4, 2, 2, 12, 2, 2, 2, 16, 2, 18, 2, 4, 2, 2, 2, 24, 4, 2, 2, 4, 2, 2, 2, 32, 2, 2, 2, 36, 2, 2, 2, 8, 2, 6, 2, 4, 2, 2, 2, 48, 4, 10, 2, 4, 2, 2, 2, 8, 2, 2, 2, 4, 2, 2, 2, 64, 2, 6, 2, 4, 2, 10, 2, 72, 2, 2, 18, 4, 2, 2, 2, 16, 8, 2, 2, 12, 2, 2, 2, 8, 2, 6, 10, 4, 2, 2, 2, 96, 2, 2, 4, 20

Offset: 1

Author

Antti Karttunen, Aug 16 2023

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..16384
• Index entries for sequences related to binary expansion of n
• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A163511, A348717, A364255, A364297.

Programs

PARI

A163511(n) = if(!n,1,my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
A348717(n) = if(1==n, 1, 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));
A364949(n) = gcd(A348717(n),A348717(A163511(n)));

Formula

a(n) = gcd(A348717(n), A364297(n)).

a(2*n) = A364255(2*n) = 2*A364255(n). (Edited Sep 03 2023)