%I A137864
%S A137864 1,3,5,7,33,131,373,855,1697,3043,5061,7943,11905,17187,24053,32791,
%T A137864 43713,57155,73477,93063,116321,143683,175605,212567,255073,303651,
%U A137864 358853,421255,491457,570083,657781,755223,863105,982147
%N A137864 a(n) = n^4-10n^3+35n^2-48n+23.
%C A137864 This sequence appears at first to be the sequence of odd numbers but 
               then rapidly becomes something different altogether. It is a good 
               example of why more than a few terms are needed to check a hypothesis.
%C A137864 Useful for practising the method of finite differences
%D A137864 A. Watson and J. Mason, Mathematics as a Constructive Activity, LEA London, 
               2005, p. 162.
%H A137864 Author?, <a href="http://www.teachers.ash.org.au/mikemath/numseqfindiff/
               note2.pdf">Method of Finite Differences</a>.
%F A137864 O.g.f.: -x*(1-2*x+2*x^3+23*x^4)/(-1+x)^5 . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), 
               Feb 19 2008
%e A137864 a(5) = 33 the first term that breaks with the odd number pattern.
%Y A137864 Cf. A005408.
%Y A137864 Sequence in context: A002396 A029508 A095714 this_sequence A069969 A067232 
               A106115
%Y A137864 Adjacent sequences: A137861 A137862 A137863 this_sequence A137865 A137866 
               A137867
%K A137864 easy,more,nonn
%O A137864 1,2
%A A137864 Christopher Martin (christopher.j.martin(AT)gmail.com), Feb 17 2008
%E A137864 More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 19 2008