Search: id:A137864 Results 1-1 of 1 results found. %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?, Method of Finite Differences. %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 Search completed in 0.001 seconds