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 A256045 Triangle read by rows: order of all-2s configuration on the n X k sandpile grid graph. 6
 2, 3, 1, 7, 7, 8, 11, 5, 71, 3, 26, 9, 679, 77, 52, 41, 13, 769, 281, 17753, 29, 97, 47, 3713, 4271, 726433, 434657, 272, 153, 17, 8449, 2245, 33507, 167089, 46069729, 901, 362, 123, 81767, 8569, 24852386, 265721, 8118481057, 190818387, 73124, 571, 89, 93127, 18061, 20721019, 4213133, 4974089647, 1031151241, 1234496016491, 89893 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Laura Florescu, Daniela Morar, David Perkinson, Nicholas Salter and Tianyuan Xu, Sandpiles and Dominos, Electronic Journal of Combinatorics, Volume 22(1), 2015. David Perkinson, Lecture 15: Sandpiles, PCMI 2008 Undergraduate Summer School. FORMULA From Andrey Zabolotskiy, Oct 22 2021: (Start) It seems that T(k, 1) = A005246(k+2). For the formula for T(k, 2), see the theorem by Morar and Perkinson in Perkinson's slides. T(n, k) divides A348566(n, k). (End) EXAMPLE Triangle begins: [2] [3, 1] [7, 7, 8] [11, 5, 71, 3] [26, 9, 679, 77, 52] [41, 13, 769, 281, 17753, 29] [97, 47, 3713, 4271, 726433, 434657, 272] [153, 17, 8449, 2245, 33507, 167089, 46069729, 901] [362, 123, 81767, 8569, 24852386, 265721, 8118481057, 190818387, 73124] [571, 89, 93127, 18061, 20721019, 4213133, 4974089647, 1031151241, 1234496016491, 89893] ... CROSSREFS Main diagonal gives A256046, A256043, and A256047. Cf. A005246, A195549, A348566. Sequence in context: A328398 A085588 A118008 * A173459 A121637 A247370 Adjacent sequences:  A256042 A256043 A256044 * A256046 A256047 A256048 KEYWORD nonn,tabl AUTHOR N. J. A. Sloane, Mar 15 2015 EXTENSIONS Column 1 added by Andrey Zabolotskiy, Oct 22 2021 STATUS approved

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Last modified December 7 17:17 EST 2021. Contains 349582 sequences. (Running on oeis4.)