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A134137
Alternating row sums of triangle A049352 (S1p(4)).
1
1, 3, 9, 15, -159, -3021, -36903, -381249, -3212415, -12995901, 315857961, 12457515663, 304888863969, 6280156107315, 113710631625081, 1717208752084479, 15528594345353217, -265033870991715069, -22048996644203788215
OFFSET
1,2
FORMULA
a(n)=sum(A049352(n,m)*(-1)^(m-1),m=1..n), n>=1.
E.g.f.: 1-exp(-x*(3-3*x+x^2)/(3*(1-x)^3)). Cf. e.g.f. first column of A049352.
CROSSREFS
Sequence in context: A083556 A015664 A272621 * A174179 A076362 A336970
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang Oct 12 2007
STATUS
approved