%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