OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened
FORMULA
T(n,k) = k*(k+1)*n*(k*n-n+k+2)/6, k>=1, n>=1.
EXAMPLE
Northwest corner:
1.....5....14....30....55
2.....12...36....80....150
3.....21...66....150...285
4.....32...104...240...460
5.....45...150...350...675
MATHEMATICA
(See A185780.)
f[n_, k_] := k*(k + 1)*n*(k*n - n + k + 2)/6; Table[f[n - k + 1, k], {n, 10}, {k, n, 1, -1}] // Flatten (* G. C. Greubel, Jul 12 2017 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Feb 03 2011
STATUS
approved