A293452 Triangle T(n,k) read by rows: T(n,k) is the number of iterations to reach a final state for an n X k lattice of sandpiles on a torus according to rules specified in A249872.

0, 1, 7, 2, 14, 28, 7, 35, 65, 133, 10, 47, 86, 198, 316, 22, 86, 134, 331, 487, 913, 28, 106, 164, 399, 696, 1099, 1360, 50, 159, 288, 589, 930, 1518, 1798, 2987, 60, 187, 336, 681, 1070, 1966, 2320, 3432, 4340, 95, 265, 515, 1052, 1386, 2430, 3475, 4484, 5977, 7495, 110, 303, 584, 1184, 1556, 2718

Offset

1,3

Links

Joerg Arndt, Table of n, a(n) for n = 1..5050 (rows 1..50)

Wikipedia, Abelian sandpile model

Formula

T(n,n) = A249872(n).

Conjecture: T(n,1) = A023855(n).

Example

Triangle begins:
0
1, 7
2, 14, 28
7, 35, 65, 133
10, 47, 86, 198, 316
22, 86, 134, 331, 487, 913
28, 106, 164, 399, 696, 1099, 1360
50, 159, 288, 589, 930, 1518, 1798, 2987
60, 187, 336, 681, 1070, 1966, 2320, 3432, 4340
95, 265, 515, 1052, 1386, 2430, 3475, 4484, 5977, 7495
...

Crossrefs

Cf. A249872.

Sequence in context: A040048 A070429 A050092 * A030406 A336194 A332209

Adjacent sequences: A293449 A293450 A293451 * A293453 A293454 A293455

Keyword

nonn,tabl

Author

Joerg Arndt, Oct 09 2017

Status

approved