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A228643
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Triangle read by rows: T(n,1) = n * (n - 1) + 1 and for k: 1 < k <= n: T(n,k) = T(n,k-1) + T(n-1,k-1).
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4
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1, 3, 4, 7, 10, 14, 13, 20, 30, 44, 21, 34, 54, 84, 128, 31, 52, 86, 140, 224, 352, 43, 74, 126, 212, 352, 576, 928, 57, 100, 174, 300, 512, 864, 1440, 2368, 73, 130, 230, 404, 704, 1216, 2080, 3520, 5888, 91, 164, 294, 524, 928, 1632, 2848, 4928, 8448
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table;
graph;
refs;
listen;
history;
text;
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OFFSET
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1,2
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COMMENTS
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T(n,1) = A002061(n); T(n,2) = A005893(n-1) for n > 1;
T(n,n) = A007466(n).
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LINKS
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Reinhard Zumkeller, Rows n = 1..100 of table, flattened
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EXAMPLE
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. 1: 1
. 2: 3, 4
. 3: 7, 10, 14
. 4: 13, 20, 30, 44
. 5: 21, 34, 54, 84, 128
. 6: 31, 52, 86,140, 224, 352
. 7: 43, 74,126,212, 352, 576, 928
. 8: 57,100,174,300, 512, 864,1440,2368
. 9: 73,130,230,404, 704,1216,2080,3520, 5888
. 10: 91,164,294,524, 928,1632,2848,4928, 8448,14336
. 11: 111,202,366,660,1184,2112,3744,6592,11520,19968,34304
. 12: 133,244,446,812,1472,2656,4768,8512,15104,26624,46592,80896.
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PROG
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(Haskell)
a228643 n k = a228643_tabl !! (n-1) !! (k-1)
a228643_row n = a228643_tabl !! (n-1)
a228643_tabl = map fst $ iterate
(\(row, x) -> (scanl (+) (x * (x - 1) + 1) row, x + 1)) ([1], 2)
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CROSSREFS
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Sequence in context: A108579 A332822 A287410 * A304066 A296994 A236475
Adjacent sequences: A228640 A228641 A228642 * A228644 A228645 A228646
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KEYWORD
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nonn,tabl
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AUTHOR
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J. M. Bergot and Reinhard Zumkeller, Aug 29 2013
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STATUS
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approved
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