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 A007548 Shifts 3 places left under exponentiation. (Formerly M1485) 4
 1, 1, 1, 1, 2, 5, 15, 53, 213, 961, 4808, 26405, 157965, 1022573, 7122441, 53118601, 422362118, 3566967917, 31887812715, 300848966213, 2987359924149, 31143724848889, 340113005563268, 3882897830626949, 46254432194746377, 573938743829923349, 7406289665830324689 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Alois P. Heinz, Table of n, a(n) for n = 1..200 M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to arXiv version] M. Bernstein and N. J. A. Sloane, Some canonical sequences of integers, Linear Alg. Applications, 226-228 (1995), 57-72; erratum 320 (2000), 210. [Link to Lin. Alg. Applic. version together with omitted figures] FORMULA E.g.f. A(x) satisfies differential equation A'''(x)=exp(A(x)), A'(0)=1, A''(0)=1, A'''(0)=1. - Vladimir Kruchinin, Nov 19 2011 MAPLE exptr:= proc(p) local g; g:= proc(n) option remember; p(n) +add(binomial(n-1, k-1) *p(k) *g(n-k), k=1..n-1) end: end: b:= exptr(a): a:= n-> `if`(n<=2, 1, b(n-3)): seq(a(n), n=1..30); # Alois P. Heinz, Oct 07 2008 MATHEMATICA Exptr[p_] := Module[{g}, g[n_] := g[n] = p[n] + Sum [Binomial[n-1, k-1]*p[k]*g[n-k], {k, 1, n-1}]; g]; b = Exptr [a]; a[n_] := If[n <= 2, 1, b[n-3]]; Table[a[n], {n, 1, 30}] (* Jean-François Alcover, May 06 2014, after Alois P. Heinz *) CROSSREFS Sequence in context: A107589 A249892 A006790 * A328431 A120567 A263779 Adjacent sequences:  A007545 A007546 A007547 * A007549 A007550 A007551 KEYWORD nonn,eigen AUTHOR STATUS approved

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Last modified February 27 18:47 EST 2020. Contains 332308 sequences. (Running on oeis4.)