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 A145225 T(n,k) is the number of odd permutations (of an n-set) with exactly k fixed points. 0
 0, 0, 0, 1, 0, 0, 0, 3, 0, 0, 6, 0, 6, 0, 0, 20, 30, 0, 10, 0, 0, 135, 120, 90, 0, 15, 0, 0, 924, 945, 420, 210, 0, 21, 0, 0, 7420, 7392, 3780, 1120, 420, 0, 28, 0, 0, 66744, 66780, 33264, 11340, 2520, 756, 0, 36, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 LINKS Bashir Ali and A. Umar, Some combinatorial properties of the alternating group, Southeast Asian Bulletin Math. 32 (2008), 823-830. FORMULA T(n,k) = C(n,k)*A145221(n-k) E.g.f.: (x^(k+2)*exp(-x))/(2*(k!)*(1-x)). EXAMPLE Triangle starts: 0; 0, 0; 1, 0, 0; 0, 3, 0, 0; 6, 0, 6, 0, 0; 20, 30, 0, 10, 0; ... CROSSREFS Row sum is A001710 for n > 1, sum of Row1=sum of Row2 = 0. T(n, 0) is A145221, T(n, 1) is A145222, T(n, 2) is A145223. Sequence in context: A062688 A067181 A321429 * A061480 A220692 A048962 Adjacent sequences:  A145222 A145223 A145224 * A145226 A145227 A145228 KEYWORD nonn,tabl AUTHOR Abdullahi Umar, Oct 10 2008 STATUS approved

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Last modified June 26 04:02 EDT 2019. Contains 324368 sequences. (Running on oeis4.)