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A054640 Divisor sum of primorials = A000203[A002110[n]]. 6
3, 12, 72, 576, 6912, 96768, 1741824, 34836480, 836075520, 25082265600, 802632499200, 30500034969600, 1281001468723200, 56364064623820800, 2705475101943398400, 146095655504943513600, 8765739330296610816000 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Divisor sum of primorials = Product[Prime[i]+1; {i,1,n}]

FORMULA

a(n+1)=a(n)*Prime[n+1]=a(n)*A028815; (quotient=nth prime+1 starting with 2)

MAPLE

with (numtheory):a:=n->mul(1+ithprime(j), j=1..n):seq(a(n), n=1..17); [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Aug 24 2008]

CROSSREFS

A002110, A000203, A028815, A054641.

Sequence in context: A020530 A147998 A052676 * A139486 A060906 A163860

Adjacent sequences:  A054637 A054638 A054639 * A054641 A054642 A054643

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), May 15 2000

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Last modified February 15 21:16 EST 2012. Contains 205856 sequences.