A120787 - OEIS

A120787

Denominators of partial sums of Catalan numbers scaled by powers of 1/20.

1, 20, 200, 1600, 80000, 1600000, 16000000, 1280000000, 2560000000, 256000000000, 2560000000000, 102400000000000, 1024000000000000, 4096000000000000, 40960000000000000, 6553600000000000000

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Numerators are given under A120786.

LINKS

Table of n, a(n) for n=0..15.

FORMULA

a(n)=denominator(r(n)), with the rationals r(n):=sum(C(k)/20^k,k=0..n) with C(k):=A000108(k) (Catalan numbers).

CROSSREFS

Sequence in context: A035474 A103261 A120796 * A223753 A099197 A041766

Adjacent sequences: A120784 A120785 A120786 * A120788 A120789 A120790

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang, Jul 20 2006

STATUS

approved