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A117677 a(n) = number of divisors of n^2 (excluding 1 and n^2). 4
0, 1, 1, 3, 1, 7, 1, 5, 3, 7, 1, 13, 1, 7, 7, 7, 1, 13, 1, 13, 7, 7, 1, 19, 3, 7, 5, 13, 1, 25, 1, 9, 7, 7, 7, 23, 1, 7, 7, 19, 1, 25, 1, 13, 13, 7, 1, 25, 3, 13, 7, 13, 1, 19, 7, 19, 7, 7, 1, 43, 1, 7, 13, 11, 7, 25, 1, 13, 7, 25, 1, 33, 1, 7, 13, 13, 7, 25, 1, 25, 7, 7, 1, 43, 7, 7, 7, 19, 1, 43, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
LINKS
FORMULA
a(n) = A070824(n^2). - Ray Chandler, Nov 08 2018
MATHEMATICA
Join[{0}, DivisorSigma[0, Range[2, 100]^2]-2] (* Harvey P. Dale, Oct 17 2016 *)
CROSSREFS
Equals A048691(n) - 2 for n>1. Cf. A117679, A117010, A070824.
Sequence in context: A268670 A360331 A227873 * A324377 A038870 A347234
KEYWORD
easy,nonn
AUTHOR
Mark Taggart (mt2612f(AT)aol.com), Apr 12 2006
STATUS
approved

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Last modified March 29 06:13 EDT 2024. Contains 371265 sequences. (Running on oeis4.)