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 A171418 Expansion of (1+x)^4/(1-x). 10
 1, 5, 11, 15, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS For n>=4 a(n)=2^4=16. This sequence is the transform of A115291 by the following transform T: T(u_0,u_1,u_2,u_3,u_4,...)=(u_0,u_0+u_1, u_1+u_2,u_2+u_3,aso); we observe that T(A040000)=A113311 and also T(A113311)=A115291... Also continued fraction expansion of (55305+sqrt(65))/46231. - Bruno Berselli, Sep 23 2011 REFERENCES (Revue) Richard Choulet, Une nouvelle formule de combinatoire?, Mathematique et Pedagogie, 157(2006), p. 53-60. LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 Index entries for linear recurrences with constant coefficients, signature (1). FORMULA a(n) = sum(C(5,n-2*k),k=0..floor(n/2)). EXAMPLE a(3)=C(5,3-0)+C(5,3-2)=10+5=15. MAPLE m:=5:for n from 0 to m+1 do a(n):=sum('binomial(m, n-2*k)', k=0..floor(n/2)): od : seq(a(n), n=0..m+1); CROSSREFS Cf. A040000, A113311, A115291, A171440, A171441, A171442, A171443. Sequence in context: A137002 A091718 A078002 * A213444 A314002 A137004 Adjacent sequences:  A171415 A171416 A171417 * A171419 A171420 A171421 KEYWORD nonn,easy AUTHOR Richard Choulet, Dec 08 2009 EXTENSIONS Definition rewritten by Bruno Berselli, Sep 23 2011 STATUS approved

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Last modified October 19 11:00 EDT 2019. Contains 328216 sequences. (Running on oeis4.)