login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A128936 a(n) = binomial(n, sum_digits_n). 2
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; text; internal format)
OFFSET

0,11

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..10000 (terms 1..1000 from G. C. Greubel)

EXAMPLE

a(12) = binomial(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=0..38); # Emeric Deutsch, May 04 2007

MATHEMATICA

Table[Binomial[n, Total[IntegerDigits[n]]], {n, 1, 40}] (* G. C. Greubel, Feb 10 2019 *)

PROG

(PARI) a(n) = binomial(n, sumdigits(n)); \\ Michel Marcus, Feb 10 2019

(Sage) [binomial(n, sum(int(d) for d in str(n))) for n in (1..40)] # G. C. Greubel, Feb 10 2019

CROSSREFS

Cf. A007953.

Sequence in context: A008502 A008492 A023035 * A000582 A229890 A243744

Adjacent sequences:  A128933 A128934 A128935 * A128937 A128938 A128939

KEYWORD

nonn,base

AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Apr 27 2007

EXTENSIONS

a(0)=1 prepended by Seiichi Manyama, Apr 24 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 3 01:39 EDT 2020. Contains 333195 sequences. (Running on oeis4.)