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A092517 Product of tau-values for consecutive integers. 11
2, 4, 6, 6, 8, 8, 8, 12, 12, 8, 12, 12, 8, 16, 20, 10, 12, 12, 12, 24, 16, 8, 16, 24, 12, 16, 24, 12, 16, 16, 12, 24, 16, 16, 36, 18, 8, 16, 32, 16, 16, 16, 12, 36, 24, 8, 20, 30, 18, 24, 24, 12, 16, 32, 32, 32, 16, 8, 24, 24, 8, 24, 42, 28, 32, 16, 12, 24, 32, 16, 24, 24, 8, 24, 36 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Number of divisors of the n-th oblong number. - Ray Chandler, Jun 23 2008

Number of positive solutions (x,y) for which n/x + (n+1)/y = 1. - Michel Lagneau, Jan 16 2014

LINKS

Ray Chandler, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A000005(n)*A000005(n+1) = A000005(n*(n+1)) = A000005(A002378(n)) = 2*A063123(n).

MAPLE

with(numtheory): seq(tau(n)*tau(n+1), n=1..73); # Zerinvary Lajos, Jan 22 2007

PROG

(MAGMA) [ NumberOfDivisors(n^2+n) : n in [1..100]]; // Vincenzo Librandi, Apr 03 2011

(PARI) a(n) = numdiv(n^2+n); \\ Michel Marcus, Jan 11 2020

CROSSREFS

Cf. A063440, A083539.

Sequence in context: A133691 A111973 A161655 * A128558 A090346 A267460

Adjacent sequences:  A092514 A092515 A092516 * A092518 A092519 A092520

KEYWORD

nonn,changed

AUTHOR

Reinhard Zumkeller, Apr 06 2004

EXTENSIONS

Extended by Ray Chandler, Jun 23 2008

STATUS

approved

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Last modified January 21 05:23 EST 2020. Contains 331104 sequences. (Running on oeis4.)