A297703 The Genocchi triangle read by rows, T(n,k) for n>=0 and 0<=k<=n.

1, 1, 1, 2, 3, 3, 8, 14, 17, 17, 56, 104, 138, 155, 155, 608, 1160, 1608, 1918, 2073, 2073, 9440, 18272, 25944, 32008, 36154, 38227, 38227, 198272, 387104, 557664, 702280, 814888, 891342, 929569, 929569, 5410688, 10623104, 15448416, 19716064, 23281432, 26031912

Offset

0,4

Links

Table of n, a(n) for n=0..41.

Example

The triangle starts:
0: [     1]
1: [     1,      1]
2: [     2,      3,      3]
3: [     8,     14,     17,     17]
4: [    56,    104,    138,    155,    155]
5: [   608,   1160,   1608,   1918,   2073,   2073]
6: [  9440,  18272,  25944,  32008,  36154,  38227,  38227]
7: [198272, 387104, 557664, 702280, 814888, 891342, 929569, 929569]

Prog

(Julia)
function A297703Triangle(len::Int)
    A = fill(BigInt(0), len+2); A[2] = 1
    for n in 2:len+1
        for k in n:-1:2 A[k] += A[k+1] end
        for k in 2: 1:n A[k] += A[k-1] end
        println(A[2:n])
    end
end
println(A297703Triangle(9))
(Python)
from functools import cache
@cache
def T(n):  # returns row n
    if n == 0: return [1]
    row = [0] + T(n - 1) + [0]
    for k in range(n, 0, -1): row[k] += row[k + 1]
    for k in range(2, n + 2): row[k] += row[k - 1]
    return row[1:]
for n in range(9): print(T(n))  # Peter Luschny, Jun 03 2022

Crossrefs

Row sums are A005439 with offset 0.

T(n,0) = A005439 with A005439(0) = 1.

T(n,n) = A110501 with offset 0.

Cf. A001469, A014781, A099959, A226158.

Sequence in context: A108692 A157126 A357655 * A263464 A267563 A166994

Adjacent sequences: A297700 A297701 A297702 * A297704 A297705 A297706

Keyword

nonn,tabl

Author

Peter Luschny, Jan 03 2018

Status

approved