The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A307996 Expansion of e.g.f. exp(1 - exp(x)*(1 - 2*x)). 0
 1, 1, 4, 15, 73, 410, 2591, 18165, 139266, 1155509, 10293729, 97815520, 986113613, 10499247005, 117603042220, 1381191356979, 16958788930317, 217132031279842, 2892337840164051, 40002168264724193, 573363461815952802, 8502905138072937073, 130268705062115090965, 2058969680487762098496 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..23. FORMULA a(0) = 1; a(n) = Sum_{k=1..n} (2*k - 1)*binomial(n-1,k-1)*a(n-k). MATHEMATICA nmax = 23; CoefficientList[Series[Exp[1 - Exp[x] (1 - 2 x)], {x, 0, nmax}], x] Range[0, nmax]! a[n_] := a[n] = Sum[(2 k - 1) Binomial[n - 1, k - 1] a[n - k], {k, 1, n}]; a[0] = 1; Table[a[n], {n, 0, 23}] CROSSREFS Cf. A000248, A000354, A003727, A005408, A275707. Sequence in context: A303229 A340355 A356009 * A230741 A020082 A020037 Adjacent sequences: A307993 A307994 A307995 * A307997 A307998 A307999 KEYWORD nonn AUTHOR Ilya Gutkovskiy, May 09 2019 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 May 26 20:29 EDT 2024. Contains 372844 sequences. (Running on oeis4.)