A286585 a(n) = A053735(A048673(n)).

1, 2, 1, 3, 2, 4, 2, 4, 3, 3, 3, 5, 1, 5, 2, 5, 2, 4, 2, 4, 2, 4, 3, 6, 5, 6, 3, 6, 4, 7, 3, 6, 3, 3, 3, 5, 3, 5, 5, 5, 4, 3, 4, 5, 4, 6, 1, 7, 5, 6, 4, 7, 2, 8, 4, 7, 4, 5, 3, 8, 4, 4, 4, 7, 4, 6, 2, 4, 5, 6, 3, 6, 4, 6, 5, 6, 4, 6, 4, 6, 7, 5, 3, 4, 5, 7, 6, 6, 5, 5, 4, 7, 3, 8, 1, 8, 5, 6, 3, 7, 6, 7, 2, 8

Offset

1,2

Links

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

Formula

a(n) = A053735(A048673(n)).

For all n >= 0, a(A000079(n)) = n+1.

Prog

(Scheme) (define (A286585 n) (A053735 (A048673 n)))
(Python)
from sympy.ntheory.factor_ import digits
from sympy import factorint, nextprime
from operator import mul
def a053735(n): return sum(digits(n, 3)[1:])
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 a053735(a048673(n))
print([a(n) for n in range(1, 101)]) # Indranil Ghosh, Jun 12 2017

Crossrefs

Cf. A000079, A048673, A053735, A286582, A286583, A286584, A286586.

Sequence in context: A355140 A286632 A308453 * A028914 A204539 A302604

Adjacent sequences: A286582 A286583 A286584 * A286586 A286587 A286588

Keyword

nonn

Author

Antti Karttunen, May 31 2017

Status

approved