

A108501


Number of factorizations of 4*n into even numbers.


3



2, 3, 2, 5, 2, 4, 2, 7, 3, 4, 2, 7, 2, 4, 3, 11, 2, 6, 2, 7, 3, 4, 2, 12, 3, 4, 3, 7, 2, 7, 2, 15, 3, 4, 3, 12, 2, 4, 3, 12, 2, 7, 2, 7, 4, 4, 2, 19, 3, 6, 3, 7, 2, 8, 3, 12, 3, 4, 2, 14, 2, 4, 4, 22, 3, 7, 2, 7, 3, 7, 2, 21, 2, 4, 4, 7, 3, 7, 2, 19, 4, 4, 2, 14, 3, 4, 3, 12, 2, 11, 3, 7, 3, 4, 3, 30, 2
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OFFSET

1,1


LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000


EXAMPLE

a(6)=4 because 6*4=24 can be factored as 24=12*2=6*4=6*2*2.


MAPLE

with(numtheory):
b:= proc(n, i) option remember; `if`(n<=i, 1, 0)+
add(`if`(d<=i and irem(d, 2)=0 and irem(n/d, 2)=0,
b(n/d, min(d, i)), 0), d=divisors(n) minus {1, n})
end:
a:= n> b(4*n$2):
seq(a(n), n=1..100); # Alois P. Heinz, Feb 17 2015


CROSSREFS

Cf. A001055, A108502, A108503.
Sequence in context: A073751 A319431 A258581 * A166226 A263978 A326810
Adjacent sequences: A108498 A108499 A108500 * A108502 A108503 A108504


KEYWORD

nonn


AUTHOR

Christian G. Bower, Jun 06 2005


STATUS

approved



