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 A173004 Antidiagonal triangle sequence based on recursion: f(n,a)=a*f(n-1,a)+n*f(n-2,a) 0
 0, 0, 1, 0, 1, 1, 0, 1, 2, 4, 0, 1, 3, 7, 8, 0, 1, 4, 12, 22, 28, 0, 1, 5, 19, 48, 79, 76, 0, 1, 6, 28, 92, 204, 290, 272, 0, 1, 7, 39, 160, 463, 900, 1133, 880, 0, 1, 8, 52, 258, 940, 2404, 4128, 4586, 3328 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,9 COMMENTS Row sums are: {0, 1, 2, 7, 19, 67, 228, 893, 3583, 15705,...}. LINKS FORMULA f(n,a)=a*f(n-1,a)+n*f(n-2,a); t(n,m)=antidiagonal(f(n,a)) EXAMPLE {0}, {0, 1}, {0, 1, 1}, {0, 1, 2, 4}, {0, 1, 3, 7, 8}, {0, 1, 4, 12, 22, 28}, {0, 1, 5, 19, 48, 79, 76}, {0, 1, 6, 28, 92, 204, 290, 272}, {0, 1, 7, 39, 160, 463, 900, 1133, 880}, {0, 1, 8, 52, 258, 940, 2404, 4128, 4586, 3328} MATHEMATICA f[0, a_] := 0; f[1, a_] := 1; f[n_, a_] := f[n, a] = a*f[n - 1, a] + n*f[n - 2, a]; m1 = Table[f[n, a], {n, 0, 10}, {a, 1, 11}]; Table[Table[m1[[m, n - m + 1]], {m, 1, n}], {n, 1, 10}]; Flatten[%] CROSSREFS Sequence in context: A083741 A258761 A256245 * A118343 A309148 A226031 Adjacent sequences:  A173001 A173002 A173003 * A173005 A173006 A173007 KEYWORD nonn,tabl,uned AUTHOR Roger L. Bagula, Feb 07 2010 STATUS approved

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Last modified January 22 14:23 EST 2021. Contains 340362 sequences. (Running on oeis4.)