A350062 a(n) is the smallest number with the same prime signature as A156552(n), with a(1) = 0.

0, 1, 2, 2, 4, 2, 8, 2, 6, 4, 16, 2, 32, 2, 6, 6, 64, 2, 128, 2, 12, 6, 256, 2, 12, 6, 6, 6, 512, 6, 1024, 2, 6, 6, 12, 8, 2048, 2, 30, 6, 4096, 2, 8192, 2, 6, 24, 16384, 2, 24, 4, 30, 2, 32768, 2, 36, 2, 30, 12, 65536, 2, 131072, 6, 6, 12, 12, 6, 262144, 6, 6, 2, 524288, 6, 1048576, 6, 6, 6, 24, 6, 2097152, 2, 30, 6

Offset: 1

Author

Antti Karttunen, Jan 29 2022

Keywords

• nonn

Links

• Index entries for sequences computed from indices in prime factorization

Crossrefs

Cf. A046523, A156552, A350063, A350064 (rgs-transform).

Programs

PARI

A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
A156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
A350062(n) = if(1==n,0,A046523(A156552(n)));

Formula

a(n) = A046523(A156552(n)).