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 A122591 a(n) = 2*a(n - 1) - a(n - 2) - (a(n - 1)^2 + a(n - 2)^2). 0
 1, 1, 3, 15, 261, 68853, 4740941175, 22476523239032929731, 505194096914787342916581691483319031273, 255221075557547546310804864838512137564534415781651685947633570258183940865705 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 REFERENCES S. M. Ulam, Problems in Modern Mathematics, John Wiley and Sons, New York, 1960, page 110 LINKS MATHEMATICA a[0] = 1; a[1] = 1; a[n_] := a[n] = 2*a[n - 1] - a[n - 2] +(a[n - 1]^2 + a[n - 2]^2); Table[a[n], {n, 0, 10}] CROSSREFS Sequence in context: A277626 A050474 A051179 * A326263 A120607 A013352 Adjacent sequences:  A122588 A122589 A122590 * A122592 A122593 A122594 KEYWORD nonn AUTHOR Roger L. Bagula, Sep 19 2006 EXTENSIONS Edited by N. J. A. Sloane, Sep 21 2006 STATUS approved

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Last modified May 11 21:35 EDT 2021. Contains 343808 sequences. (Running on oeis4.)