OFFSET
3,2
LINKS
V. I. Arnold, The calculus of snakes and the combinatorics of Bernoulli, Euler and Springer numbers of Coxeter groups, Uspekhi Mat. nauk., 47 (#1, 1992), 3-45 = Russian Math. Surveys, Vol. 47 (1992), 1-51. English version.
J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A (1996) 44-54 (Abstract, pdf, ps).
C. Poupard, De nouvelles significations énumeratives des nombres d'Entringer, Discrete Math., 38 (1982), 265-271.
EXAMPLE
This is a sub-triangle of A008282, starting in row 3 of A008282 and then proceeding as a regular triangle.
[ 3] 1
[ 4] 2, 4
[ 5] 5, 10, 14
[ 6] 16, 32, 46, 56
[ 7] 61, 122, 178, 224, 256
[ 8] 272, 544, 800, 1024, 1202, 1324
[ 9] 1385, 2770, 4094, 5296, 6320, 7120, 7664
[10] 7936, 15872, 23536, 30656, 36976, 42272, 46366, 49136
[11] 50521, 101042, 150178, 196544, 238816, 275792, 306448, 329984, 345856
MAPLE
T := proc(n, k) option remember; if k = 0 then `if`(n = 0, 1, 0) else
T(n, k - 1) + T(n - 1, n - k) fi end:
seq(seq(T(n, k-2), k = 3..n), n = 3..11); # Peter Luschny, Feb 17 2021
MATHEMATICA
T[n_, k_] := T[n, k] = If[k == 0, If[n == 0, 1, 0],
T[n, k - 1] + T[n - 1, n - k]];
Table[Table[T[n, k - 2], {k, 3, n}], {n, 3, 11}] // Flatten (* after Peter Luschny *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
STATUS
approved