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A068904 a(n) = binomial(sigma(n),tau(n)), where sigma(n) is the sum and tau(n) the number of divisors of n (A000203, A000005). 4
1, 3, 6, 35, 15, 495, 28, 1365, 286, 3060, 66, 376740, 91, 10626, 10626, 169911, 153, 3262623, 190, 5245786, 35960, 58905, 276, 2558620845, 4495, 111930, 91390, 32468436, 435, 11969016345, 496, 67945521, 194580, 316251, 194580, 783768050065, 703, 487635 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1024 terms from Antti Karttunen)

MAPLE

with(numtheory); P:=proc(i) local a, n; for n from 1 by 1 to i do a:=binomial(sigma(n), tau(n)); print(a); od; end: P(20); # Paolo P. Lava, Dec 12 2008

MATHEMATICA

Table[Binomial[DivisorSigma[1, n], DivisorSigma[0, n]], {n, 50}] (* Carl Najafi, Oct 10 2011 *)

PROG

(PARI) a(n)=binomial(sigma(n), numdiv(n)) \\ Charles R Greathouse IV, Feb 19 2013

CROSSREFS

Cf. A068905, A068903, A204292.

Sequence in context: A249875 A308557 A134748 * A309774 A244296 A143046

Adjacent sequences:  A068901 A068902 A068903 * A068905 A068906 A068907

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 06 2002

EXTENSIONS

More terms from Carl Najafi, Oct 10 2011

STATUS

approved

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Last modified August 8 16:31 EDT 2022. Contains 356016 sequences. (Running on oeis4.)