OFFSET
0,3
COMMENTS
Compare the first and 2nd binomial transforms of this sequence:
first binomial={1,1,-2,1,4,1,-62,1,1384,1,-50522,1,2702764,..};
2nd binomial={1,2,1,-1,1,17,1,-271,1,7937,1,-353791,..};
to that of the first and 2nd binomial transforms of A090145:
first binomial of A090145={1,0,1,-3,1,15,1,-273,1,7935,1,..};
2nd binomial of A090145={1,1,2,1,-4,1,62,1,-1384,1,50522,..}.
Comparison reveals this e.g.f. relation of the two sequences:
e.g.f.: exp(x)*G090158(x) + exp(2x)*G090145(x) = 2 + 2*sinh(x);
e.g.f.: exp(2*x)*G090158(x) - exp(x)*G090145(x) = 2*sinh(x);
thus G090158(x) = 2*(1+sinh(x) + exp(x)*sinh(x))/(exp(x)*(1+exp(2*x)))
G090145(x) = 2*((1+sinh(x))*exp(x) - sinh(x))/(exp(x)*(1+exp(2*x))).
FORMULA
E.g.f.: 2*(1 + sinh(x) + exp(x)*sinh(x)) / (exp(x)*(1 + exp(2*x))).
a(2n) = 1 - 2^(2n);
1 = sum_{k=0..2n-1} C(2n-1, k)*a(k);
1 = sum_{k=0..2n} 2^(2n-k)*C(2n, k)*a(k).
MATHEMATICA
With[{nn=30}, CoefficientList[Series[2 (1+Sinh[x]+Exp[x]Sinh[x])/ (Exp[x] (1+ Exp[2x])), {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Feb 13 2016 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Paul D. Hanna, Nov 22 2003
STATUS
approved