Search: id:A138354 Results 1-1 of 1 results found. %I A138354 %S A138354 1,0,3,1,21,26,215,498,2821,9040,43695,165375,752785,3101970,13881803, %T A138354 59837183,267860685,1184749704,5337504263,23996776941,108964583121, %U A138354 495544446410,2267450194443,10402298479276,47926692348121 %N A138354 Central moment sequence of tr(A^4) in USp(4). %C A138354 Binomial transform of A018224. %C A138354 If A is a random matrix in the compact group USp(4) (4 X 4 complex are unitary and symplectic), then a(n)=E[(tr(A^4)+1)^n] is the nth central moment of the trace of A^4, since E[tr(A^4)] = -1 (see A018224). %D A138354 Kiran S. Kedlaya and Andrew V. Sutherland, "Hyperelliptic curves, L-polynomials and random matrices", preprint, 2008. %H A138354 Kiran S. Kedlaya and Andrew V. Sutherland, Hyperelliptic curves, L-polynomials and random matrices. %F A138354 a(n)=(1/2)Integral_{x=0..Pi,y=0..Pi}(2cos(4x)+2cos(4y)+1)^n(2cos(x)-2cos(y))^2(2/ Pi*sin^2(x))(2/Pi*sin^2(y))dxdy. a(n)=Sum_{i=0..n}binomial(n,i)A018224(i). %e A138354 a(3) = 1 because E[(tr(A^4)+1)^3] = 1. %e A138354 a(3) = 1*A018224(0) + 3*A018224(1) + 3*A018224(2) + 1*A018224(1) %e A138354 = 1*1 + 3*(-1) + 3*4 + 1*(-9) = 1. %Y A138354 Cf. A018224. %Y A138354 Sequence in context: A000369 A136236 A113090 this_sequence A010291 A027477 A137330 %Y A138354 Adjacent sequences: A138351 A138352 A138353 this_sequence A138355 A138356 A138357 %K A138354 nonn %O A138354 0,3 %A A138354 Andrew V. Sutherland (drew(AT)math.mit.edu), Mar 16 2008, Mar 31 2008 Search completed in 0.001 seconds