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 A228515 Nonlinear recursion: a(n) = a(n-1) + Product_{i=1..(n-1)/2} a(n-2i+1)-a(n-2i). 0
 1, 2, 4, 6, 8, 12, 20, 52, 308, 8500, 2105652, 17181974836, 36028814200938804, 618970019678718951650500916, 22300745198530623760505737951367313156481332 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Initial conditions: a(1)=1; a(2)=1; a(3)=4; With a(3)=3, the recursion gives the positive integers. LINKS Table of n, a(n) for n=1..15. MATHEMATICA a[1]:= 1; a[2]:= 2; a[3]:= 4; a[n_Integer]:=a[n]=a[n-1]+ Times@@Table[(a[n-2i+1]-a[n-2i]), {i, 1, (n-1)/2}]; Table[a[n], {n, 1, 15}] CROSSREFS Sequence in context: A323114 A362231 A118563 * A363145 A164145 A354530 Adjacent sequences: A228512 A228513 A228514 * A228516 A228517 A228518 KEYWORD nonn,easy AUTHOR Olivier Gérard, Aug 24 2013 STATUS approved

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Last modified August 11 10:37 EDT 2024. Contains 375068 sequences. (Running on oeis4.)