The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A185731 Array by antidiagonals: T(n,k)=F*(k*n-n+3*k+13), where F = k*(k+1)*(k+2)*n*(n+1)*(n+2)/576. 2
 1, 5, 4, 15, 21, 10, 35, 65, 55, 20, 70, 155, 175, 115, 35, 126, 315, 425, 375, 210, 56, 210, 574, 875, 925, 700, 350, 84, 330, 966, 1610, 1925, 1750, 1190, 546, 120, 495, 1530, 2730, 3570, 3675, 3010, 1890, 810, 165, 715, 2310, 4350, 6090, 6860, 6370, 4830, 2850, 1155, 220, 1001, 3355, 6600 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS This is the accumulation array of A185730.  (See A144112 for the definition of accumulation array.) LINKS G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened FORMULA T(n,k) = F*(k*n-n+3*k+13), where F = k*(k+1)*(k+2)*n*(n+1)*(n+2)/576. EXAMPLE Northwest corner: 1.....5....15....35....70 4.....21...65....155...315 10....55...175...425...875 20....115..375...925...1925 MATHEMATICA f[n_, k_]:=k(1+k)n(1+n)(7+2k-n+k*n)/36; TableForm[Table[f[n, k], {n, 1, 10}, {k, 1, 15}]]  (* A185730 *) Table[f[n-k+1, k], {n, 14}, {k, n, 1, -1}]//Flatten s[n_, k_]:=Sum[f[i, j], {i, 1, n}, {j, 1, k}]; (* acc. arr. of {f(n, k)} *) Factor[s[n, k]]  (* formula for A185731 *) TableForm[Table[s[n, k], {n, 1, 10}, {k, 1, 15}]] (* array A185731 *) Table[s[n-k+1, k], {n, 14}, {k, n, 1, -1}]//Flatten (* A185731 *) CROSSREFS Cf. A144112, A185730. Sequence in context: A203976 A213566 A143129 * A177765 A337122 A282068 Adjacent sequences:  A185728 A185729 A185730 * A185732 A185733 A185734 KEYWORD nonn,tabl AUTHOR Clark Kimberling, Feb 01 2011 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 13 04:09 EDT 2021. Contains 343836 sequences. (Running on oeis4.)