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A009217 E.g.f. exp(sin(x)^2) (even powers only). 0
1, 2, 4, -88, -1136, 46112, 1098304, -103251328, -1963486976, 585781985792, -5685626878976, -6083058037577728, 447306486332821504, 87514624808197824512, -19369074730552627675136 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
LINKS
FORMULA
a(n)=2*sum(k=1..n, (sum(i=0..k, (2*i-2*k)^(2*n)*binomial(2*k,i)*(-1)^(n+k-i)))/(4^k*k!)). - Vladimir Kruchinin, Jun 01 2011
MATHEMATICA
Exp[ Sin[ x ]^2 ] (* Even Part *)
PROG
(Maxima)
a(n):=2*sum((sum((2*i-2*k)^(2*n)*binomial(2*k, i)*(-1)^(n+k-i), i, 0, k))/(4^k*k!), k, 1, n); /* Vladimir Kruchinin, Jun 01 2011 */
CROSSREFS
Sequence in context: A121103 A018397 A259137 * A015170 A013146 A116310
KEYWORD
sign
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved

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Last modified November 28 22:38 EST 2023. Contains 367422 sequences. (Running on oeis4.)