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A076105
a(1)=1 (first row) and then the n-th row of this triangle contains the least set of n unused natural numbers whose sum is a multiple of the sum of the previous row.
6
1, 2, 3, 4, 5, 6, 7, 8, 9, 21, 10, 11, 12, 13, 44, 14, 15, 16, 17, 18, 100, 19, 20, 22, 23, 24, 25, 47, 26, 27, 28, 29, 30, 31, 32, 157, 33, 34, 35, 36, 37, 38, 39, 40, 68, 41, 42, 43, 45, 46, 48, 49, 50, 51, 305, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 155, 62, 63, 64, 65, 66, 67
OFFSET
1,2
COMMENTS
The first (n-1) terms of the n-th row contain n-1 smallest natural numbers which have not occurred earlier and the last term is chosen to satisfy the requirement. Permutation A094280 is defined similarly, but the sum of the next row must be greater than that of the current row.
EXAMPLE
1;
2, 3;
4, 5, 6;
7, 8, 9, 21;
10, 11, 12, 13, 44;
14, 15, 16, 17, 18, 100;
CROSSREFS
Sequence in context: A079170 A330927 A319387 * A094280 A082323 A069571
KEYWORD
nonn,tabl
AUTHOR
Amarnath Murthy, Oct 08 2002
EXTENSIONS
More terms from David Wasserman, Apr 02 2005
Description edited by Antti Karttunen, Aug 25 2006
STATUS
approved