A286586 a(n) = A006047(A048673(n)).

2, 3, 2, 6, 4, 9, 3, 12, 8, 6, 6, 18, 2, 18, 3, 24, 4, 12, 4, 12, 4, 9, 6, 36, 18, 27, 6, 36, 12, 54, 6, 48, 6, 6, 8, 24, 6, 18, 24, 24, 12, 6, 9, 18, 12, 36, 2, 72, 18, 27, 12, 54, 4, 81, 12, 72, 12, 18, 8, 108, 12, 9, 12, 96, 9, 36, 4, 12, 18, 36, 8, 48, 16, 27, 24, 36, 9, 36, 12, 48, 72, 18, 6, 12, 24, 54, 27, 36, 24, 18, 16, 72, 8, 81, 2

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..8192

Formula

a(n) = A006047(A048673(n)).

For n >= 0, a(A000079(n)) = A042950(n).

Prog

(Scheme) (define (A286586 n) (A006047 (A048673 n)))
(Python)
from sympy.ntheory.factor_ import digits
from sympy import factorint, nextprime
from operator import mul
from functools import reduce
def a006047(n):
    d=digits(n, 3)
    return n + 1 if n<3 else reduce(mul, [1 + d[i] for i in range(1, len(d))])
def a048673(n):
    f = factorint(n)
    return 1 if n==1 else (1 + reduce(mul, [nextprime(i)**f[i] for i in f]))//2
def a(n): return a006047(a048673(n))
print([a(n) for n in range(1, 101)]) # Indranil Ghosh, Jun 12 2017

Crossrefs

Cf. A000079, A006047, A042950, A048673, A286585, A286587.

Sequence in context: A157224 A097914 A286633 * A113710 A286587 A054126

Adjacent sequences: A286583 A286584 A286585 * A286587 A286588 A286589

Keyword

nonn

Author

Antti Karttunen, May 31 2017

Status

approved