A365230 Triangle T(n, k), n > 0, k = 1..n, read by rows and filled the greedy way with distinct positive integers such that T(n, k) is a multiple of T(k, 1).

1, 2, 4, 3, 6, 9, 5, 8, 12, 10, 7, 14, 15, 20, 21, 11, 16, 18, 25, 28, 22, 13, 24, 27, 30, 35, 33, 26, 17, 32, 36, 40, 42, 44, 39, 34, 19, 38, 45, 50, 49, 55, 52, 51, 57, 23, 46, 48, 60, 56, 66, 65, 68, 76, 69, 29, 54, 63, 70, 77, 88, 78, 85, 95, 92, 58

Offset

1,2

Comments

As a flat sequence, this is a permutation of the positive integers (as each row starts with the least value not yet in the sequence); see A365231 for the inverse.

Links

Rémy Sigrist, Table of n, a(n) for n = 1..10011 (rows for n = 1..141 flattened)

Rémy Sigrist, PARI program

Index entries for sequences that are permutations of the natural numbers

Example

Triangle T(n, k) begins:
         1;
         2,  4;
         3,  6,  9;
         5,  8, 12, 10;
         7, 14, 15, 20, 21;
        11, 16, 18, 25, 28, 22;
        13, 24, 27, 30, 35, 33, 26;
        17, 32, 36, 40, 42, 44, 39, 34;
        19, 38, 45, 50, 49, 55, 52, 51, 57;
        ...................................
T(k, 1)  1   2   3   5   7  11  13  17  19

Prog

(PARI) See Links section.

Crossrefs

See A364884 and A365232 for similar sequences.

Cf. A365231 (inverse).

Sequence in context: A370923 A179216 A192176 * A191711 A163280 A056537

Adjacent sequences: A365227 A365228 A365229 * A365231 A365232 A365233

Keyword

nonn,tabl

Author

Rémy Sigrist, Aug 27 2023

Status

approved