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A142589
Square array T(n,m) = Product_{i=0..m} (1+n*i) read by antidiagonals.
4
1, 1, 1, 1, 2, 1, 1, 6, 3, 1, 1, 24, 15, 4, 1, 1, 120, 105, 28, 5, 1, 1, 720, 945, 280, 45, 6, 1, 1, 5040, 10395, 3640, 585, 66, 7, 1, 1, 40320, 135135, 58240, 9945, 1056, 91, 8, 1, 1, 362880, 2027025, 1106560, 208845, 22176, 1729, 120, 9, 1, 1, 3628800, 34459425, 24344320, 5221125, 576576, 43225, 2640, 153, 10, 1
OFFSET
0,5
COMMENTS
Antidiagonal sums are {1, 2, 4, 11, 45, 260, 1998, 19735, 244797, 3729346, 68276276, ...}.
EXAMPLE
The transpose of the array is:
1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 2, 3, 4, 5, 6, 7, 8, 9,
1, 6, 15, 28, 45, 66, 91, 120, 153, ... A000384
1, 24, 105, 280, 585, 1056, 1729, 2640, 3825, ... A011199
1, 120, 945, 3640, 9945, 22176, 43225, 76560, 126225,... A011245
1, 720, 10395, 58240, 208845, 576576, 1339975, 2756160,...
/ | \ \
MAPLE
T:= (n, k)-> `if`(n=0, 1, mul(j*k+1, j=0..n)):
seq(seq(T(n-k, k), k=0..n), n=0..12); # G. C. Greubel, Mar 05 2020
MATHEMATICA
T[n_, k_]= If[n==0, 1, Product[1 + k*i, {i, 0, n}]]; Table[T[n-k, k], {n, 0, 10}, {k, 0, n}]//Flatten
PROG
(PARI) T(n, k) = if(n==0, 1, prod(j=0, n, j*k+1) );
for(n=0, 12, for(k=0, n, print1(T(n-k, k), ", "))) \\ G. C. Greubel, Mar 05 2020
(Magma)
function T(n, k)
if k eq 0 or n eq 0 then return 1;
else return (&*[j*k+1: j in [0..n]]);
end if; return T; end function;
[T(n-k, k): k in [0..n], n in [0..12]]; // G. C. Greubel, Mar 05 2020
(Sage)
def T(n, k):
if (k==0 and n==0): return 1
else: return product(j*k+1 for j in (0..n))
[[T(n-k, k) for k in (0..n)] for n in (0..12)] # G. C. Greubel, Mar 05 2020
CROSSREFS
Cf. A000142, A006882(2n-1) = A001147, A007661(3n-2) = A007559, A007662(4n-3) = A007696, A153274.
Sequence in context: A181644 A144351 A213936 * A284308 A369435 A172400
KEYWORD
nonn,tabl
AUTHOR
EXTENSIONS
Edited by M. F. Hasler, Oct 28 2014
More terms added by G. C. Greubel, Mar 05 2020
STATUS
approved