This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A159553 a(n) = Sum_{k=0..n} binomial(n,k) * gcd(n,k). 3
 2, 6, 12, 28, 40, 144, 140, 536, 864, 2560, 2068, 12720, 8216, 45192, 78660, 182832, 131104, 933984, 524324, 3698240, 4890648, 13345816, 8388652, 67390464, 60129600, 225470544, 279938160, 1032462256, 536870968, 5018059200 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS For the purpose of this sequence, gcd(n,0) = n, for all positive integers n. a(n) is a multiple of n, for all nonnegative integers n. LINKS Michael De Vlieger, Table of n, a(n) for n = 1..3317 FORMULA a(n) = A159068(n) + n. a(n) = 2^n * Sum_{d|n} (phi(d)/d) * Sum_{k=1..d} (-1)^(k*n/d)*cos(k*Pi/d)^n. MAPLE A159553 := proc(n) add(binomial(n, k)*gcd(k, n), k=0..n) ; end: seq(A159553(n), n=1..40) ; # R. J. Mathar, Apr 29 2009 MATHEMATICA Table[Sum[Binomial[n, k] GCD[n, k], {k, 0, n}], {n, 30}] (* Michael De Vlieger, Oct 30 2017 *) CROSSREFS Cf. A159068, A159554. Sequence in context: A185961 A290674 A290419 * A222970 A112510 A284449 Adjacent sequences:  A159550 A159551 A159552 * A159554 A159555 A159556 KEYWORD nonn AUTHOR Leroy Quet, Apr 14 2009 EXTENSIONS Extended by R. J. Mathar, Apr 29 2009 Ambiguous term a(0) removed by Max Alekseyev, Jan 09 2015 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 September 20 01:58 EDT 2019. Contains 327207 sequences. (Running on oeis4.)