A331279 a(n) = A122111(A006047(n)).

1, 2, 4, 2, 3, 6, 4, 6, 9, 2, 3, 6, 3, 5, 10, 6, 10, 15, 4, 6, 9, 6, 10, 15, 9, 15, 25, 2, 3, 6, 3, 5, 10, 6, 10, 15, 3, 5, 10, 5, 7, 14, 10, 14, 21, 6, 10, 15, 10, 14, 21, 15, 21, 35, 4, 6, 9, 6, 10, 15, 9, 15, 25, 6, 10, 15, 10, 14, 21, 15, 21, 35, 9, 15, 25, 15, 21, 35, 25, 35, 49, 2, 3, 6, 3, 5, 10, 6, 10, 15, 3, 5, 10, 5, 7

Offset

0,2

Links

Antti Karttunen, Table of n, a(n) for n = 0..19683

Formula

a(n) = A122111(A006047(n)).

For all n >= 0, A056239(a(n)) = A053735(n).

Prog

(PARI)
A006047(n) = { my(m=1, d); while(n, d = (n%3); m *= (1+d); n = (n-d)/3); m; };
A064989(n) = {my(f); f = factor(n); if((n>1 && f[1, 1]==2), f[1, 2] = 0); for (i=1, #f~, f[i, 1] = precprime(f[i, 1]-1)); factorback(f)};
A122111(n) = if(1==n, n, prime(bigomega(n))*A122111(A064989(n)));
A331279(n) = A122111(A006047(n));

Crossrefs

Cf. A006047, A056239, A053735, A122111.

Sequence in context: A271320 A354739 A348486 * A151849 A360373 A141387

Adjacent sequences: A331276 A331277 A331278 * A331280 A331281 A331282

Keyword

nonn

Author

Antti Karttunen, Jan 13 2020

Status

approved