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A128936 a(n)=binomial(n, sum_digits_n). 1
1, 1, 1, 1, 1, 1, 1, 1, 1, 10, 55, 220, 715, 2002, 5005, 11440, 24310, 48620, 92378, 190, 1330, 7315, 33649, 134596, 480700, 1562275, 4686825, 13123110, 34597290, 4060, 31465, 201376, 1107568, 5379616, 23535820, 94143280, 348330136, 1203322288 (list; graph; refs; listen; history; internal format)
OFFSET

1,10

EXAMPLE

a(12)=binom(12,3)=220

MAPLE

P:=proc(n) local a, i, k, w; for i from 1 by 1 to n do w:=0; k:=i; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; a:=binomial(i, w); print(a); od; end: P(100);

a:=proc(n) local nn, s: nn:=convert(n, base, 10): s:=sum(nn[j], j=1..nops(nn)): binomial(n, s): end: seq(a(n), n=1..38); - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 04 2007

CROSSREFS

Sequence in context: A008502 A008492 A023035 * A000582 A145459 A034241

Adjacent sequences:  A128933 A128934 A128935 * A128937 A128938 A128939

KEYWORD

nonn

AUTHOR

Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), Apr 27 2007

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Last modified February 13 19:49 EST 2012. Contains 205536 sequences.