Search: id:A123025 Results 1-1 of 1 results found. %I A123025 %S A123025 1,1,1,5,11,95,319,3895,17545,276545,1561505,30143405,204557155,4672227775, %T A123025 37024845055,976495604975,8848937968145,264630308948225,2698926080284225, %U A123025 90238935351344725,1022892984427721275,37810113912213439775,471553665821179507775 %V A123025 1,1,-1,-5,11,95,-319,-3895,17545,276545,-1561505,-30143405,204557155, 4672227775, %W A123025 -37024845055,-976495604975,8848937968145,264630308948225,-2698926080284225, %X A123025 -90238935351344725,1022892984427721275,37810113912213439775,-471553665821179507775 %N A123025 Let b(0) = 1, b(1) = 1; b(n+2) = -(n^2-n+1)*(b(n))/((n+2)*(n+1)). Then a(n) = n!*b(n). %D A123025 Richard Bronson, Schaum's Outline of Modern Introductory Differential Equations, MacGraw-Hill, New York,1973, page 107, solved problem 19.17 %t A123025 a[n_] := a[n] = -(n^2 - n - 1)*a[n - 2]/(n*(n - 1)); a[0] = 1; a[1] = 1; Table[a[n]*n!, {n, 0, 30}] %Y A123025 Sequence in context: A128454 A120778 A042761 this_sequence A053778 A030079 A066596 %Y A123025 Adjacent sequences: A123022 A123023 A123024 this_sequence A123026 A123027 A123028 %K A123025 sign %O A123025 1,4 %A A123025 Roger Bagula (rlbagulatftn(AT)yahoo.com), Sep 24 2006 %E A123025 Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 06 2009 Search completed in 0.001 seconds