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A010552
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Multiply successively by 1 (once), 2 (twice), 3 (thrice), etc.
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1
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1, 1, 2, 4, 12, 36, 108, 432, 1728, 6912, 27648, 138240, 691200, 3456000, 17280000, 86400000, 518400000, 3110400000, 18662400000, 111974400000, 671846400000, 4031078400000, 28217548800000, 197522841600000, 1382659891200000, 9678619238400000, 67750334668800000
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OFFSET
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0,3
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LINKS
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FORMULA
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a(0)=1, a(n) = a(n-1)*floor(sqrt(2*n)+1/2)) for n>0. - Alois P. Heinz, May 20 2013
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MAPLE
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a:= proc(n) option remember; `if`(n=0, 1,
a(n-1) * floor(sqrt(2*n)+1/2))
end:
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MATHEMATICA
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t = Table[n, {n, 9}, {n}] // Flatten; b[n_] := t[[n]]; a[0] = 1; a[n_] := a[n] = b[n] a[n-1]; Table[a[n], {n, 0, t // Length}] (* Jean-François Alcover, Feb 21 2016 *)
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PROG
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(PARI) lista(nn) = {na = 1; i = 0; im = 1; print1(na, ", "); while (i < nn, for (j=1, im, na *= im; print1(na, ", "); i++; ); im++; ); } \\ Michel Marcus, May 20 2013
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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