A043294 Sum of digits of binomial(2n,n).

2, 6, 2, 7, 9, 15, 12, 18, 20, 31, 21, 25, 11, 18, 27, 27, 27, 33, 39, 54, 57, 51, 45, 45, 54, 72, 74, 67, 66, 76, 77, 72, 75, 78, 90, 88, 86, 96, 83, 88, 117, 99, 99, 117, 99, 108, 90, 108, 126, 126, 117, 144, 135, 141, 156, 153, 138, 141, 153, 153, 126, 162, 156, 168

Offset

1,1

Links

Table of n, a(n) for n=1..64.

Formula

a(n) = A007953(A000984(n)). - Michel Marcus, Feb 17 2021

Example

Binomial(2*6,6)=924 and 9+2+4=15 hence a(6)=15.

Mathematica

Total[IntegerDigits[#]]&/@Table[Binomial[2n, n], {n, 70}] (* Harvey P. Dale, Jul 22 2022 *)

Prog

(PARI) a(n) = sumdigits(binomial(2*n, n)); \\ Michel Marcus, Feb 17 2021

Crossrefs

Cf. A000984, A007953.

Sequence in context: A086359 A091944 A069936 * A365260 A368522 A033641

Adjacent sequences: A043291 A043292 A043293 * A043295 A043296 A043297

Keyword

base,easy,nonn

Author

Benoit Cloitre, Mar 24 2002

Extensions

Typo in data corrected by Michel Marcus, Feb 17 2021

Status

approved