Search: id:A072946 Results 1-1 of 1 results found. %I A072946 %S A072946 1,2,6,4,12,8,24,16,48,32,96,64,192,128,384,256,768,512,1536,1024,3072, %T A072946 2048,6144,4096,12288,8192,24576,16384,49152,32768,98304,65536,196608, %U A072946 131072,393216,262144,786432,524288,1572864,1048576,3145728,2097152 %N A072946 Coefficient of the highest power of q in the expansion of nu(0)=1, nu(1)=b and for n>=2, nu(n)=b*nu(n-1)+lambda*(n-1)_q*nu(n-2) with (b,lambda)=(2, 2), where (n)_q=(1+q+...+q^(n-1)) and q is a root of unity. %C A072946 Instead of listing the coefficients of the highest power of q in each nu(n), if we listed the coefficients of the smallest power of q (i.e. constant terms), we get a weighted Fibonacci numbers described by f(0)=1, f(1)=1, for n>=2, f(n)=2f(n-1)+2f(n-2). %H A072946 M. Beattie, S. D\u{a}sc\u{a}lescu and S. Raianu, Lifting of Nichols Algebras of Type $B_2$ %F A072946 for given b and lambda, the recurrence relation is given by; t(0)=1, t(1)=b, t(2)=b^2+lambda and for n>=3, t(n)=lambda*T(n-2) %F A072946 O.g.f.: -(1+2*x+4*x^2)/(-1+2*x^2) . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 05 2007 %e A072946 nu(0)=1, nu(1)=2, nu(2)=6, nu(3)=16+4q, nu(4)=44+20q+12q^2, nu(5)=120+80q+64q^2+40q^3+8q^4, nu(6)=328+288q+280q^2+232q^3+168q^4+64q^5+24q^6. By listing the coefficients of the highest power in each nu(n) we get 1,2,6,4,12,8,24,... %Y A072946 Cf. A002605. %Y A072946 Sequence in context: A059909 A145177 A007517 this_sequence A134000 A127730 A118416 %Y A072946 Adjacent sequences: A072943 A072944 A072945 this_sequence A072947 A072948 A072949 %K A072946 nonn %O A072946 0,2 %A A072946 Y. Kelly Itakura (yitkr(AT)mta.ca), Aug 21 2002 %E A072946 More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Dec 05 2007 Search completed in 0.001 seconds