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A276679
Number of divisors of the n-th hexagonal number.
6
1, 4, 4, 6, 6, 8, 4, 16, 6, 8, 8, 12, 6, 16, 8, 10, 8, 24, 4, 24, 8, 8, 12, 16, 9, 16, 8, 24, 8, 16, 4, 36, 16, 8, 16, 18, 4, 24, 16, 16, 10, 16, 8, 24, 12, 16, 8, 40, 6, 36, 8, 12, 16, 16, 8, 32, 8, 16, 12, 48, 6, 16, 24, 14, 16, 16, 8, 48, 8, 16, 8, 48, 8
OFFSET
1,2
LINKS
FORMULA
a(n) = A000005(A000384(n)). - Omar E. Pol, Sep 13 2016
EXAMPLE
a(6) = 8 because the 6th hexagonal number is 66, which has 8 divisors: 1,2,3,6,11,22,33,66.
PROG
(PARI)
pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ n-th m-gonal number
vector(100, n, numdiv(pg(6, n)))
CROSSREFS
Number of divisors of m-gonal numbers (m = 3..10): A063440, A048691, A276678, this sequence, A276680, A276681, A276682, A276683.
Sequence in context: A196594 A190303 A175123 * A163638 A113523 A179278
KEYWORD
nonn
AUTHOR
Colin Barker, Sep 13 2016
STATUS
approved