2,1

The ZG1 matrix coefficients are defined by ZG1[2m-1,1] = 2*zeta(2m-1) for m = 2, 3, .. , and the recurrence relation ZG1[2m-1,n] = (ZG1[2m-3,n-1] - (n-1)^2*ZG1[2m-1,n-1])/(n*(n-1)) with m = .. , -2, -1, 0, 1, 2, .. and n = 1, 2, 3, .. , under the condition that n <= (m-1). As usual zeta(m) is the Riemann zeta function. For the ZG2 matrix, the even counterpart of the ZG1 matrix, see A008955.

These two formulae enable us to determine the values of the ZG1[2*m-1,n] coefficients, with m all integers and n all positive integers, but not for all. If we choose, somewhat but not entirely arbitrarily, ZG1[1,1] = 2*gamma, with gamma the Euler-Mascheroni constant, we can determine them all.

The coefficients in the columns of the ZG1 matrix, for m => 1 and n => 2, can be generated with GFZ(z;n) = (hg(n)*CFN1(z;n)*GFZ(z;n=1) + ZETA(z;n))/pg(n) with pg(n) = 6*(n-1)!* (n)!*A160476(n) and hg(n) = 6*A160476(n). For the CFN1(z;n) and the ZETA(z;n) polynomials see A160474.

The column sums cs(n) = sum(ZG1[2*m-1,n], m = 1 .. infinity), for n => 2, of the ZG1 matrix can be determined with the first Maple program. In this program we have made use of the remarkable fact that if we take ZGx[2*m-1,n] = 2, for m=>1, and ZGx[ -1,n] = ZG1[ -1,n] and assume that the recurrence relation remains the same we find that the column sums of this new matrix converge to the same values as the original cs(n).

The ZG1[2*m-1,n] matrix coefficients can be generated with the second Maple program.

The ZG1 matrix is related to the ZS1 matrix, see A160474 and the formulae below.

M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972, Chapter 23, pp. 811-812.

a(n) = numer(cs(n)) and denom(cs(n)) = A162447(n).

with cs(n) = sum(ZG1[2*m-1,n], m = 1 .. infinity) for n => 2.

GFZ(z;n) = sum( ZG1[2*m-1,n]*z^(2*m-2),m=1..infinity)

GFZ(z;n) = ZG1[ -1,n-1]/(n*(n-1))+(z^2-(n-1)^2)*GFZ(z;n-1)/(n*(n-1)) for n => 2 with GFZ(z;n=1) = -Psi(1+z) - Psi(1-z).

ZG1[ -1,n] = binomial(2*n,n)*Omega[n] = A000984(n)*A002195(n)/A002196(n).

ZG1[2*m-1,n] = b(n)*ZS1[2*m-1,n] with b(n) = binomial(2*n,n)/2^(2*n-1) for n =>1.

The first few generating functions GFZ(z;n) are:

GFZ(z;2) = (6*(1*z^2-1)*GFZ(z;1) + (-1))/12

GFZ(z;3) = (60*(z^4-5*z^2+4)*GFZ(z;1) + (51-10*z^2))/720

GFZ(z;4) = (1260*(z^6-14*z^4+49*z^2-36)*GFZ(z;1) + (-10594+2961*z^2-210*z^4))/181440

restart; nmax:=14: mmax:=nmax: jn:=nmax: im:=nmax: Omega[0]:=1: for n from 1 to nmax do for j from 1 to jn do cfn1[1, j]:=1 end do: for i from 2 to im do cfn1[i, 1]:=0 end do: for j from 2 to jn do for i from 2 to im do cfn1[i, j]:=cfn1[i-1, j-1]*(j-1)^2+cfn1[i, j-1] end do end do: Omega[n]:= (sum((-1)^(k+n+1)*(bernoulli(2*k)/(2*k))*cfn1[n-k+1, n], k=1..n))/(2*n-1)! end do: for n from 1 to nmax do ZG1[ -1, n]:= binomial(2*n, n)*Omega[n] od: for n from 1 to nmax do ZGx[ -1, n]:=ZG1[ -1, n] od: for m from 1 to mmax do ZGx[2*m-1, 1]:=2 od: for n from 2 to nmax do for m from 1 to mmax do ZGx[2*m-1, n]:=(((ZGx[2*m-3, n-1]-(n-1)^2*ZGx[2*m-1, n-1])/(n*(n-1)))) od; s(n):=0: for m from 1 to mmax do s(n):=s(n)+ZGx[2*m-1, n] od: od: seq(s(n), n=2..nmax);

restart; nmax:=5; ncol:=3; Digits:=20: mmax:=nmax: jn:=nmax: im:=nmax: Omega[0]:=1: for n from 1 to nmax do for j from 1 to jn do cfn1[1, j]:=1 end do: for i from 2 to im do cfn1[i, 1]:=0 end do: for j from 2 to jn do for i from 2 to im do cfn1[i, j]:=cfn1[i-1, j-1]*(j-1)^2+cfn1[i, j-1] end do end do: end do: ZG1[1, 1]:=evalf(2*gamma): for m from 1 to mmax do ZG1[1-2*m, 1]:=-bernoulli(2*m)/m od: for m from 2 to mmax do ZG1[2*m-1, 1]:=evalf(2*Zeta(2*m-1)) od: for n from 1 to nmax do for m from -mmax to mmax do ZG1[2*m-1, n]:=sum((-1)^(k+1)*cfn1[k, n]*ZG1[2*m-(2*n-2*k+1), 1] /((n-1)!*(n)!), k=1..n) od; od; for m from -mmax+ncol to mmax do ZG1[2*m-1, ncol]:=ZG1[2*m-1, ncol] od;

See A162447 for the denominators of the column sums.

The pg(n) and hg(n) sequences lead to A160476.

The ZG1[ -1, n] coefficients lead to A000984, A002195 and A002196.

The ZETA(z, n) polynomials and the ZS1 matrix lead to the Zeta triangle A160474.

The CFN1(z, n), the cfn1(m, n) and the ZG2 matrix lead to A008955.

The b(n) sequence equals A001790(n)/ A120777(n-1) for n=>1.

Cf. A001620 (gamma) and A010790 (n!*(n+1)!).

Cf. A162440 (EG1 matrix), A162443 (BG1 matrix) and A162448 (LG1 matrix)

Sequence in context: A134498 A142122 A009010 this_sequence A075672 A069876 A126086

Adjacent sequences: A162443 A162444 A162445 this_sequence A162447 A162448 A162449

easy,frac,sign

Johannes W. Meijer (meijgia(AT)hotmail.com), Jul 06 2009