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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A043294 Sum of digits of binomial(2n,n). 1
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS 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. PROG (PARI) a(n) = sumdigits(binomial(2*n, n)); \\ Michel Marcus, Feb 17 2021 CROSSREFS Cf. A000984, A007953. Sequence in context: A086359 A091944 A069936 * A033641 A153190 A010240 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

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.

Last modified December 5 10:11 EST 2021. Contains 349543 sequences. (Running on oeis4.)