A074135 Triangle read by rows: for 1 <= k < n, a(n, k) is the least positive integer not already used. a(n, n) is the least positive integer not already used that makes the row sum a multiple of n.

1, 2, 4, 3, 5, 7, 6, 8, 9, 13, 10, 11, 12, 14, 18, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 40, 36, 37, 38, 39, 41, 42, 43, 44, 49, 45, 46, 47, 48, 50, 51, 52, 53, 54, 64, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 75, 66, 67, 68, 69, 70, 71

Offset

1,2

Comments

Alternative (but equivalent) definition: In the following square array, numbers (not occurring earlier) are entered like this a(1, 1), a(1, 2), a(2, 1), a(3, 1), a(2, 2), a(1, 3), a(1, 4), a(2, 3), a(3, 2), a(4, 1), a(5, 1), a(4, 2), ... such that the n-th diagonal sum is a multiple of n. 1 2 7 6 18... 4 5 8 14... 3 9 12... 13 11... 10... ... sequence contains terms as they are entered.

Links

Table of n, a(n) for n=1..72.

Crossrefs

Cf. A074132, A074133, A074134, A074136.

Cf. A082017, A082018, A082019, A082020.

Sequence in context: A166266 A011295 A082016 * A074146 A262478 A236348

Adjacent sequences: A074132 A074133 A074134 * A074136 A074137 A074138

Keyword

nonn,easy,tabl,less

Author

Amarnath Murthy, Aug 27 2002

Extensions

Edited and extended by David Wasserman, Oct 31 2006

Further edited by N. J. A. Sloane Jan 17 2009 at the suggestion of R. J. Mathar

Status

approved