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A276683 Number of divisors of the n-th 10-gonal number.

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%I A276683 #10 Jun 05 2021 11:28:08
%S A276683 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,
%T A276683 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,
%U A276683 32,24,8,4,36,4,24,16,28,8,32,8,12,24,16,4,64,6,8
%N A276683 Number of divisors of the n-th 10-gonal number.
%H A276683 Colin Barker, <a href="/A276683/b276683.txt">Table of n, a(n) for n = 1..1000</a>
%F A276683 a(n) = A000005(A001107(n)).
%e A276683 a(4) = 6 because the 4th 10-gonal number is 52, which has 6 divisors: 1,2,4,13,26,52.
%t A276683 DivisorSigma[0,PolygonalNumber[10,Range[80]]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 05 2021 *)
%o A276683 (PARI)
%o A276683 pg(m, n) = (n^2*(m-2)-n*(m-4))/2 \\ n-th m-gonal number
%o A276683 vector(150, n, numdiv(pg(10,n)))
%Y A276683 Cf. A000005, A001107.
%Y A276683 Cf. A063440 (m=3), A048691 (m=4), A276678 (m=5), A276679 (m=6), A276680 (m=7), A276681 (m=8), A276682 (m=9).
%K A276683 nonn
%O A276683 1,2
%A A276683 _Colin Barker_, Sep 13 2016