A082019 Diagonal of square array T(n,k) with T(1,1) = 1 where antidiagonals are filled alternating upwards and downwards with the smallest number not already used such that the n-th antidiagonal sum is a multiple of n.

1, 5, 12, 25, 41, 60, 85, 112, 145, 180, 221, 264, 313, 365, 420, 481, 544, 613, 684, 761, 840, 925, 1012, 1105, 1200, 1301, 1404, 1513, 1624, 1741, 1860, 1985, 2112, 2245, 2380, 2521, 2664, 2813, 2964, 3121, 3281, 3444, 3613, 3784, 3961, 4140, 4325, 4512

Offset

1,2

Links

Table of n, a(n) for n=1..48.

Example

T(n,k) begins:
1,   2,  7,  6, 18, 15, ...
4,   5,  8, 14, 16, 27, ...
3,   9, 12, 17, 26, 31, ...
13, 11, 19, 25, 32, 42, ...
10, 20, 24, 33, 41, 50, ...
21, 23, 34, 39, 51, 60, ...

Crossrefs

Cf. A074135, A082017, A082018, A082002, A082003, A082004, A082005.

Sequence in context: A081501 A355947 A274629 * A336877 A212058 A303854

Adjacent sequences: A082016 A082017 A082018 * A082020 A082021 A082022

Keyword

nonn

Author

Amarnath Murthy, Apr 05 2003

Extensions

Edited and more terms from Alois P. Heinz, Oct 26 2011

Status

approved