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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..18.

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-Fran├žois Alcover, Jul 14 2017, adapted from Maple *)

CROSSREFS

See the triangles in A059433 and A059434.

Sequence in context: A307082 A178089 A002449 * A288607 A086584 A211604

Adjacent sequences:  A059427 A059428 A059429 * A059431 A059432 A059433

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 31 2001

STATUS

approved

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Last modified September 25 13:01 EDT 2020. Contains 337344 sequences. (Running on oeis4.)