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 A134751 Hankel transform of expansion of (1/(1-x^2))c(x/(1-x^2)), where c(x) is the g.f. of A000108. 5
 1, 2, 8, 32, 256, 4096, 65536, 2097152, 134217728, 8589934592, 1099511627776, 281474976710656, 72057594037927936, 36893488147419103232, 37778931862957161709568, 38685626227668133590597632 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Hankel transform of A105864. The sequence 1,1,2,8,... with general term 2^floor(n^2/3) is the Hankel transform of A109033. [From Paul Barry, Dec 14 2008] a(n)=4*e(n-1)*e(n-3)/e(n-4). Somos-4 sequence associated to e.g. y^2=1-8x+16x^2-8x^3. [From Paul Barry, Nov 27 2009] LINKS FORMULA a(n)=2^floor((n+1)^2/3); a(n)=Product{k=1..n, (5/3-2*cos(2*pi*k/3)/3)^(n-k+1)}; a(n)=Product{k=1..n, A130196(k)^(n-k+1)}; CROSSREFS Sequence in context: A048855 A262480 A062797 * A139014 A063505 A085466 Adjacent sequences:  A134748 A134749 A134750 * A134752 A134753 A134754 KEYWORD easy,nonn AUTHOR Paul Barry, Nov 08 2007 STATUS approved

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Last modified July 30 15:29 EDT 2021. Contains 346359 sequences. (Running on oeis4.)