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%I #15 Mar 15 2017 20:23:19
%S 0,1,2,2,-4,-16,0,96,192,-384,-3840,-3840,69120,184320,-1290240,
%T -5160960,25804800,134184960,-557383680,-3530096640,13005619200,
%U 96613171200,-326998425600,-2779486617600,8828957491200,84365593804800,-255058771968000,-2703622982860800,7855810176614400
%N a[0] = 0; a[1] = 1; if n is odd then a[n] = 2*a[n - 1] - ( n - 1)*a[n - 2] otherwise a[n] = 2*(a[n - 1] - (n - 2)*a[n - 2])].
%D E. S. R. Gopal, Specific Heats at Low Temperatures, Plenum Press, New York, 1966, pages 36-40.
%H Robert Israel, <a href="/A122598/b122598.txt">Table of n, a(n) for n = 0..804</a>
%F a(n) = If[Mod[n, 2] == 1, 2*a(n - 1) - (n - 1)*a(n - 2), 2*(a(n - 1) - (n - 2)*a(n - 2))]
%p f:= proc(n) option remember;
%p if n::odd then 2*procname(n-1) - (n-1)*procname(n-2)
%p else 2*procname(n-1) - 2*(n-2)*procname(n-2)
%p fi
%p end proc:
%p f(0):= 0: f(1):= 1:
%p map(f, [$0..100]); # _Robert Israel_, Mar 15 2017
%t a[0] = 0; a[1] = 1; a[n_] := a[n] = If[Mod[n, 2] == 1, 2*a[n - 1] - ( n - 1)*a[n - 2], 2*(a[n - 1] - (n - 2)*a[n - 2])] b = Table[a[n], {n, 0, 30}]
%t nxt[{n_,a_,b_}]:={n+1,b,If[EvenQ[n],2*b-n*a,2(b-(n-1)a)]}; Transpose[ NestList[ nxt,{1,0,1},30]][[2]] (* _Harvey P. Dale_, Dec 15 2014 *)
%Y Cf. A000898, A121966.
%K sign
%O 0,3
%A _Roger L. Bagula_, Sep 19 2006
%E Edited by _N. J. A. Sloane_, Oct 01 2006
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