%I #8 Oct 04 2015 22:30:09
%S 1,3,-21,-255,-478677,-7152407,1291535081,21021866227,
%T -8367123104756933,-125486744208053623,22639240870533272321,
%U 368298497943774746859,1120119534438107659394201,17585651607496479804464699,-4001938301481614696345053989,-68798954684172515260606005119,-1021530045274545215678840405648561149029,-15322943216340426957307389817178091600759,2767316465763270287090903125069152428833649,45031940338831118856335051343515754947640891
%N Quadrisection of A262940: a(n) = A262940(4*n+1) for n>=0.
%C a(n) = -A262940(4*n-1) for n>=1.
%H Paul D. Hanna, <a href="/A262939/b262939.txt">Table of n, a(n) for n = 0..255</a>
%o (PARI) {a(n) = local(A=[1, 1]); for(k=3, 4*n+2, A=concat(A, 0); m=2^valuation(k, 2); A[k] = 1 - Vec(Ser(A)^m)[k]/m ); A[4*n+2]}
%o for(n=0, 32, print1(a(n), ", "))
%Y Cf. A262940.
%K sign
%O 0,2
%A _Paul D. Hanna_, Oct 04 2015