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A160479 The ZL(n) sequence of the Zeta and Lambda triangles A160474 and A160487 +0
6
10, 21, 2, 11, 13, 1, 34, 57, 5, 23, 1, 1, 29, 31, 2, 1, 37, 1, 41, 301, 1, 47, 1, 1, 53, 3, 1, 59, 61, 1, 2, 67, 1, 71, 73, 1, 1, 79, 1, 83, 1, 1, 89, 1, 1, 1, 97, 1, 505, 103, 1, 107, 109, 11, 113, 1, 1, 1, 1, 1, 1, 127, 2, 131 (list; graph; listen)
OFFSET

3,1

COMMENT

The rather strange ZL(n) sequence rules both the Zeta and Lambda triangles.

The Zeta triangle led to the first and the Lambda triangle to the second Maple algorithm.

FORMULA

Contribution from Johannes W. Meijer (meijgia(AT)hotmail.com), Oct 07 2009: (Start)

a(n) = A160476(n)/A160476(n-1)

(End)

MAPLE

restart; nmax:=65; 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 b(n):= 4^(-n)*(2*n+1)*n*denom(Omega(n)) end do: c(1):=b(1): for n from 1 to nmax-1 do c(n+1):=lcm(c(n)*(n+1)*(2*n+3)/2, b(n+1)) end do: for n from 1 to nmax do cm(n):= c(n)*(1/6)* 4^n/(2*n+1)! end do: for n from 3 to nmax+1 do ZL(n):=cm(n-1)/cm(n-2) end do: a:=n-> ZL(n): seq(a(n), n=3..nmax+1);

restart; nmax:=65; jn:=nmax: im:=nmax: for n from 1 to nmax do for i from 2 to im do cfn2(i, 1):=0 end do: for j from 1 to jn do cfn2(1, j):=1 end do: for j from 2 to jn do for i from 2 to im do cfn2(i, j):= cfn2(i, j-1) + cfn2(i-1, j-1)*(2*j-3)^2 end do end do: Delta(n-1):=sum((1-2^(2*k-1))* (-1)^(n+1)*(-bernoulli(2*k)/(2*k))*(-1)^(k+n)*cfn2(n-k+1, n), k=1..n) /(2*4^(n-1)*(2*n-1)!) end do: for n from 1 to nmax do b(n):= (2*n)*(2*n-1)*denom(Delta(n-1))/ (2^(2*n)*(2*n-1)) end do: c(1):=b(1): for n from 1 to nmax-1 do c(n+1):=lcm(c(n)*(2*n+2)* (2*n+1), b(n+1)) end do: for n from 1 to nmax do cm(n):= c(n)/(6*(2*n)!) end do: for n from 3 to nmax+1 do ZL(n):=cm(n-1)/cm(n-2) end do: a:=n-> ZL(n): seq(a(n), n=3..nmax+1);

CROSSREFS

Cf. A160474 and A160487.

The cnf1[m, n] are the central factorial numbers A008955.

The cnf2[m, n] are the central factorial numbers A008956.

Sequence in context: A006993 A038693 A018990 this_sequence A085222 A085221 A128536

Adjacent sequences: A160476 A160477 A160478 this_sequence A160480 A160481 A160482

KEYWORD

easy,nonn

AUTHOR

Johannes W. Meijer (meijgia(AT)hotmail.com), May 24 2009

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Last modified November 27 14:50 EST 2009. Contains 167570 sequences.


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