A082017 First row 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, 2, 7, 6, 18, 15, 28, 29, 49, 45, 75, 66, 94, 91, 130, 120, 155, 153, 201, 190, 232, 231, 288, 276, 325, 326, 391, 378, 462, 435, 508, 496, 589, 561, 641, 630, 732, 703, 790, 780, 891, 861, 955, 946, 1066, 1035, 1136, 1128, 1257, 1225, 1333, 1326, 1464, 1431

Offset

1,2

Links

Table of n, a(n) for n=1..54.

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, A082018, A082019, A082020, A082002, A082003, A082004, A082005.

Sequence in context: A265495 A338041 A365007 * A072985 A371597 A082187

Adjacent sequences: A082014 A082015 A082016 * A082018 A082019 A082020

Keyword

nonn

Author

Amarnath Murthy, Apr 05 2003

Extensions

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

Status

approved