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A059430
Cumulative boustrophedon transform of 1, 1, 1, 1, ...
2
1, 2, 6, 26, 168, 1575, 20355, 347026, 7544974, 203740685, 6689616195, 262455558837, 12125816088194, 651621526430030, 40298978168771397, 2841833840854800621, 226670892373665762106, 20303920347033450136016, 2029489177032856597849714
OFFSET
0,2
FORMULA
See Maple code for precise description.
MAPLE
CBOUS2 := proc(a) option remember; local c, i, j, n, r: if whattype(a) <> list then RETURN([]); fi: n := min( nops(a), 60); for i from 0 to n-1 do c[i, 0] := a[i+1]; od; for i to n-1 do for j to i do c[i, j] := c[i, j-1] + add(c[i-1, i-r], r=1..j); od; od; RETURN([seq(c[i, i], i=0..n-1)]); end:
MATHEMATICA
nmax = 19; CBOUS2[a_List] := CBOUS2[a] = Module[{i, j, n, r }, n = Min[Length[a], nmax]; For[i = 0, i <= n - 1, i++, c[i, 0] = a[[i + 1]]]; For[i = n - 1, i <= nmax, i++, For[j = 1, j <= i, j++, c[i, j] = c[i, j - 1] + Sum[c[i - 1, i - r], {r, 1, j}]]]; Return[Table[c[i, i], {i, 0, n - 1}]]]; Table[CBOUS2[Table[1, {n}]], {n, 0, nmax}] // Last (* Jean-François Alcover, Jul 14 2017, adapted from Maple *)
CROSSREFS
See the triangles in A059433 and A059434.
Sequence in context: A178089 A363003 A002449 * A288607 A086584 A351288
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 31 2001
STATUS
approved