This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A191237 E.g.f. exp(x+x^3+x^5) 2
 1, 1, 1, 7, 25, 181, 1201, 5251, 57457, 469225, 4340161, 50118751, 412902601, 5544552157, 69259632625, 816044592091, 12518563864801, 152563427413201, 2401979910598657, 39326158638385975, 575414895837696121 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..125 FORMULA a(n)=n!*sum(k=1..n, ((-1)^(n-k)+1)*sum(binomial(j,(n-k)/2-j)*binomial(k,j),j,0,k)/(2*k!)), n>0, a(0)=1. MATHEMATICA a[n_] := n!*Sum[((-1)^(n - k) + 1)* Sum[ Binomial[j, (n - k)/2 - j]*Binomial[k, j], {j, 0, k}]/(2*k!), {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Feb 21 2013 *) With[{nn=20}, CoefficientList[Series[Exp[x+x^3+x^5], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Sep 21 2016 *) PROG (Maxima) a(n):=n!*sum(((-1)^(n-k)+1)*sum(binomial(j, (n-k)/2-j)*binomial(k, j), j, 0, k)/(2*k!), k, 1, n); (PARI) x='x+O('x^66); /* that many terms */ Vec(serlaplace(exp(x+x^3+x^5))) /* show terms */ /* Joerg Arndt, May 28 2011 */ CROSSREFS Sequence in context: A241714 A151491 A208425 * A088009 A208823 A197913 Adjacent sequences:  A191234 A191235 A191236 * A191238 A191239 A191240 KEYWORD nonn AUTHOR Vladimir Kruchinin, May 27 2011 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.