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A276683
Number of divisors of the n-th 10-gonal number.
6
1, 4, 4, 6, 4, 12, 6, 8, 8, 8, 4, 24, 6, 8, 12, 10, 8, 16, 4, 24, 12, 16, 4, 24, 6, 8, 20, 12, 4, 32, 6, 24, 12, 16, 8, 24, 8, 8, 16, 16, 8, 48, 6, 12, 16, 8, 8, 50, 6, 12, 12, 24, 8, 20, 16, 32, 24, 8, 4, 36, 4, 24, 16, 28, 8, 32, 8, 12, 24, 16, 4, 64, 6, 8
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OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A000005(A001107(n)).
EXAMPLE
a(4) = 6 because the 4th 10-gonal number is 52, which has 6 divisors: 1,2,4,13,26,52.
MATHEMATICA
DivisorSigma[0, PolygonalNumber[10, Range[80]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 05 2021 *)
PROG
(PARI)
pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ n-th m-gonal number
vector(150, n, numdiv(pg(10, n)))
CROSSREFS
Cf. A000005, A001107.
Cf. A063440 (m=3), A048691 (m=4), A276678 (m=5), A276679 (m=6), A276680 (m=7), A276681 (m=8), A276682 (m=9).
Sequence in context: A066560 A205031 A339719 * A247343 A071256 A078240
Adjacent sequences: A276680 A276681 A276682 * A276684 A276685 A276686
KEYWORD
nonn
AUTHOR
Colin Barker, Sep 13 2016
STATUS
approved

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Last modified November 7 03:49 EST 2024. Contains 377523 sequences.
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