%I A119879
%S A119879 1,0,1,1,0,1,0,3,0,1,5,0,6,0,1,0,25,0,10,0,1,61,0,75,0,15,0,1,0,427,0,
%T A119879 175,0,21,0,1,1385,0,1708,0,350,0,28,0,1,0,12465,0,5124,0,630,0,36,0,1,
%U A119879 50521,0,62325,0,12810,0,1050,0,45,0,1
%V A119879 1,0,1,-1,0,1,0,-3,0,1,5,0,-6,0,1,0,25,0,-10,0,1,-61,0,75,0,-15,0,1,0,
               -427,0,175,0,-21,
%W A119879 0,1,1385,0,-1708,0,350,0,-28,0,1,0,12465,0,-5124,0,630,0,-36,0,1,-50521,
               0,62325,0,
%X A119879 -12810,0,1050,0,-45,0,1
%N A119879 Exponential Riordan array (sech(x),x).
%C A119879 Row sums have e.g.f. exp(x)sech(x) (signed version of A009006). Inverse 
               of masked Pascal triangle A119467. Transforms the sequence with e.g.f. 
               g(x) to the sequence with e.g.f. g(x)*sech(x).
%F A119879 Number triangle whose k-th column has e.g.f. sech(x)*x^k/k!
%F A119879 T(n,k) = C(n,k)2^(n-k)E_{n-k}(1/2) where C(n,k) is the binomial coefficient 
               and E_{m}(x) are the Euler polynomials. [From Peter Luschny (peter(AT)luschny.de), 
               Jan 25 2009]
%e A119879 Triangle begins
%e A119879 1,
%e A119879 0, 1,
%e A119879 -1, 0, 1,
%e A119879 0, -3, 0, 1,
%e A119879 5, 0, -6, 0, 1,
%e A119879 0, 25, 0, -10, 0, 1,
%e A119879 -61, 0, 75, 0, -15, 0, 1,
%e A119879 0, -427, 0, 175, 0, -21, 0, 1,
%e A119879 1385, 0, -1708, 0, 350, 0, -28, 0, 1
%p A119879 T := (n,k) -> binomial(n,k)*2^(n-k)*euler(n-k,1/2): [From Peter Luschny 
               (peter(AT)luschny.de), Jan 25 2009]
%Y A119879 Sequence in context: A106683 A139601 A079520 this_sequence A115714 A020768 
               A104544
%Y A119879 Adjacent sequences: A119876 A119877 A119878 this_sequence A119880 A119881 
               A119882
%K A119879 easy,sign,tabl
%O A119879 0,8
%A A119879 Paul Barry (pbarry(AT)wit.ie), May 26 2006