The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A293571 E.g.f.: exp(x/(1 + x + x^2)). 4
 1, 1, -1, -5, 25, 41, -1049, 2899, 54545, -610415, -1363409, 92652011, -651996311, -10663181255, 262674487895, -529402905149, -68312606260319, 1136414207246369, 7701376416944095, -584076369474366245, 6461047290787787321, 173442620419212050761 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Robert Israel, Table of n, a(n) for n = 0..446 Robert Israel, Plot of a(n)/(n! exp(sqrt(n))) for n = 2 .. 2500 FORMULA E.g.f.: Product_{k>0} exp(x^(3*k-2)) / exp(x^(3*k-1)). a(n) = (3-2*n)*a(n-1) - 3*(n-2)*(n-1)*a(n-2) + (5-2*n)*(n-1)*(n-2)*a(n-3) - (n-4)*(n-3)*(n-2)*(n-1)*a(n-4). - Robert Israel, Jul 27 2020 MAPLE f:= gfun:-rectoproc({a(n) = (3-2*n)*a(n-1) - 3*(n-2)*(n-1)*a(n-2) + (5-2*n)*(n-1)*(n-2)*a(n-3)- (n-4)*(n-3)*(n-2)*(n-1)*a(n-4), a(0)=1, a(1)=1, a(2)=-1, a(3)=-5}, a(n), remember): map(f, [\$0..30]); # Robert Israel, Jul 27 2020 PROG (PARI) N=66; x='x+O('x^N); Vec(serlaplace(exp(x/(1+x+x^2)))) (PARI) N=66; x='x+O('x^N); Vec(serlaplace(prod(k=1, N, exp(x^(3*k-2)-x^(3*k-1))))) CROSSREFS Cf. A111884, A293572, A293573. Sequence in context: A093534 A070388 A250314 * A294256 A056872 A029490 Adjacent sequences: A293568 A293569 A293570 * A293572 A293573 A293574 KEYWORD sign AUTHOR Seiichi Manyama, Oct 12 2017 STATUS approved

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

Last modified November 28 06:02 EST 2023. Contains 367394 sequences. (Running on oeis4.)