A191702 Dispersion of A008587 (5,10,15,20,25,30,...), by antidiagonals.
1, 5, 2, 25, 10, 3, 125, 50, 15, 4, 625, 250, 75, 20, 6, 3125, 1250, 375, 100, 30, 7, 15625, 6250, 1875, 500, 150, 35, 8, 78125, 31250, 9375, 2500, 750, 175, 40, 9, 390625, 156250, 46875, 12500, 3750, 875, 200, 45, 11, 1953125, 781250, 234375, 62500, 18750
Offset: 1
Examples
Northwest corner: 1...5....25....125...625 2...10...50....250...1250 3...15...75....375...1875 4...20...100...500...2500 6...30...150...750...3750
Links
- Ivan Neretin, Table of n, a(n) for n = 1..5050 (first 100 antidiagonals, flattened)
Programs
-
Mathematica
(* Program generates the dispersion array T of the increasing sequence f[n] *) r = 40; r1 = 12; c = 40; c1 = 12; f[n_] := 5n Table[f[n], {n, 1, 30}] (* A008587 *) mex[list_] := NestWhile[#1 + 1 &, 1, Union[list][[#1]] <= #1 &, 1, Length[Union[list]]] rows = {NestList[f, 1, c]}; Do[rows = Append[rows, NestList[f, mex[Flatten[rows]], r]], {r}]; t[i_, j_] := rows[[i, j]]; TableForm[Table[t[i, j], {i, 1, 10}, {j, 1, 10}]] (* A191702 *) Flatten[Table[t[k, n - k + 1], {n, 1, c1}, {k, 1, n}]] (* A191702 *)
Formula
T(i,j) = T(i,1)*T(1,j) = (i-1+floor((i+3)/4))*5^(j-1), i>=1, j>=1.
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