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 A000472 a(n) = a(n-1)^2 + (a(n-2) + 1)*(a(n-1) - a(n-2)^2). 1
 2, 5, 28, 802, 643726, 414383582242, 171713753231982206218246, 29485613049014079571725771288849499850026859242 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES Damiani, E.; D'Antona, O.; Naldi, G.; and Pavarino, L.; Tiling bricks with bricks. Stud. Appl. Math. 83 (1990), number 2, 91-110. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..14 MAPLE A000472 := proc(n) option remember; if n<=2 then 3*n-1 else A000472(n-1)^2+(1+A000472(n-2))*(A000472(n-1)-A000472(n-2)^2); fi; end; MATHEMATICA RecurrenceTable[{a[1]==2, a[2]==5, a[n]==a[n-1]^2+(a[n-2]+1)(a[n-1]- a[n-2]^2)}, a[n], {n, 10}] (* Harvey P. Dale, Sep 29 2011 *) PROG (Magma) I:=[2, 5]; [n le 2 select I[n] else Self(n-1)^2 + (Self(n-2)+1)*(Self(n-1)-Self(n-2)^2 ): n in [1..10]]; // Vincenzo Librandi, Sep 30 2011 (Haskell) a000472 n = a000472_list !! (n-1) a000472_list = 2 : 5 : zipWith (+) (map (^ 2) \$ tail a000472_list) (zipWith (*) (map (+ 1) a000472_list) (zipWith (-) (tail a000472_list) (map (^ 2) a000472_list))) -- Reinhard Zumkeller, Oct 03 2012 CROSSREFS Sequence in context: A306893 A105787 A110497 * A248235 A358444 A327345 Adjacent sequences: A000469 A000470 A000471 * A000473 A000474 A000475 KEYWORD nonn,nice,easy AUTHOR Ottavio D'Antona [ dantona(AT)hermes.dsi.unimi.it ] STATUS approved

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Last modified March 31 15:44 EDT 2023. Contains 361668 sequences. (Running on oeis4.)