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A079784
Triangle read by rows in which the n-th row contains the smallest set of n consecutive numbers such that the r-th number in the n-th row is divisible by n-r+1. The first term of the n-th row must exceed n.
3
2, 4, 5, 9, 10, 11, 8, 9, 10, 11, 55, 56, 57, 58, 59, 54, 55, 56, 57, 58, 59, 413, 414, 415, 416, 417, 418, 419, 832, 833, 834, 835, 836, 837, 838, 839, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519, 2510, 2511, 2512, 2513, 2514, 2515, 2516, 2517, 2518, 2519
OFFSET
1,1
EXAMPLE
Triangle starts:
2;
4, 5;
9, 10, 11;
8, 9, 10, 11;
55, 56, 57, 58, 59;
54, 55, 56, 57, 58, 59;
413, 414, 415, 416, 417, 418, 419;
...
The fifth row 55,56,57,58,59 is divisible by 5,4,3,2 and 1 respectively.
MATHEMATICA
T[n_, k_] := T[n, k] = Which[n == k == 1, 2, n == k == 2, 5, n == k == 3, 11, n == k, LCM @@ Range[n] - 1, True, T[n, k + 1] - 1];
Table[T[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* Jean-François Alcover, Mar 28 2024, after comments in A079782 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Amarnath Murthy, Feb 03 2003
EXTENSIONS
Corrected and extended by Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 29 2003
STATUS
approved