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A001899 Number of divisors of n of form 5k+4. 3
0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0, 0, 2, 0, 0, 1, 2, 1, 0, 0, 1, 0, 1, 0, 2, 0, 1, 1, 1, 0, 1, 0, 2, 1, 0, 0, 2, 1, 0, 0, 1, 0, 2, 0, 2, 1, 1, 1, 1, 0, 0, 1, 2, 0, 0, 0, 2, 1, 1, 0, 3, 0, 1, 0, 2, 0, 1, 1, 1, 1, 0, 0, 3, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,25

LINKS

T. D. Noe, Table of n, a(n) for n = 0..10000

FORMULA

G.f.: Sum x^(5n+4)/(1-x^(5n+4)), n=0..inf.

MATHEMATICA

Join[{0}, Table[d = Divisors[n]; Length[Select[d, Mod[#, 5] == 4 &]], {n, 100}]] (* T. D. Noe, Aug 10 2012 *)

CROSSREFS

Sequence in context: A105964 A303051 A324044 * A059882 A303206 A094247

Adjacent sequences:  A001896 A001897 A001898 * A001900 A001901 A001902

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

EXTENSIONS

Better definition from Michael Somos, Aug 31 2004

STATUS

approved

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Last modified June 19 16:48 EDT 2019. Contains 324222 sequences. (Running on oeis4.)