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!)
 A113283 Even bisection of A113281: a(n) = A113281(2*n). 4
 1, 3, 11, 51, 255, 1325, 7039, 37951, 206799, 1135969, 6279509, 34889553, 194664283, 1089943229, 6120967411, 34463104999, 194474062663, 1099571123853, 6227893795649, 35329149864161, 200691916063033, 1141489886332555 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA G.f.: ( (1+x)/(1-x)/(1-6*x+x^2)*(1-x+(1-6*x+x^2)^(1/2))/2 )^(1/2). a(n) ~ (1 + sqrt(2))^(2*n + 1/2) / (2*sqrt(Pi*n)). - Vaclav Kotesovec, Oct 18 2020 PROG (PARI) {a(n)=local(x=X+X*O(X^n)); polcoeff( ((1+x)/(1-x)/(1-6*x+x^2)*(1-x+(1-6*x+x^2)^(1/2))/2)^(1/2), n, X)} CROSSREFS Cf. A113281, A113282, A113284. Sequence in context: A284702 A191341 A199212 * A326519 A127784 A112696 Adjacent sequences:  A113280 A113281 A113282 * A113284 A113285 A113286 KEYWORD nonn AUTHOR Paul D. Hanna, Oct 22 2005 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 03:59 EST 2021. Contains 349530 sequences. (Running on oeis4.)