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A187649
Alternated cumulative sums of the central Stirling numbers of the second kind.
1
1, 0, 7, 83, 1618, 40907, 1282745, 48046535, 2093717518, 104081678237, 5813503286418, 360468997583868, 24569735593174392, 1825998838660375668, 146956989225714933732, 12732911083544911106268, 1181728606386262922675817, 116962289970625115673808638
OFFSET
0,3
LINKS
FORMULA
a(n) = Sum_{k=0..n} (-1)^(n-k)*S(2*k,k).
a(n) ~ 2^(2*n) * n^(n-1/2) / (sqrt(2*Pi*(1-c)) * exp(n) * c^n * (2-c)^n), where c = -LambertW(-2*exp(-2)) = -A226775. - Vaclav Kotesovec, May 30 2025
MAPLE
seq(sum((-1)^(n-k)*combinat[stirling2](2*k, k), k=0..n), n=0..12);
# Alternative:
L:= [seq((-1)^n*Stirling2(2*n, n), n=0..50)]:
P:= ListTools:-PartialSums(L):
seq((-1)^(n+1)*P[n], n=1..51); # Robert Israel, Aug 25 2017
MATHEMATICA
Table[Sum[(-1)^(n-k)StirlingS2[2k, k], {k, 0, n}], {n, 0, 16}]
PROG
(Maxima) makelist(sum((-1)^(n-k)*stirling2(2*k, k), k, 0, n), n, 0, 12);
CROSSREFS
Cf. A008277 (Stirling2 triangle).
Sequence in context: A231259 A396680 A383231 * A368853 A316377 A053128
KEYWORD
nonn,easy
AUTHOR
Emanuele Munarini, Mar 12 2011
STATUS
approved