A113465 Rectangular array read by antidiagonals: a(n, d) is the smallest number that starts an arithmetic progression with common difference d of n numbers with the same number of divisors.

1, 2, 1, 33, 3, 1, 242, 3, 2, 1, 11605, 213, 119, 3, 1, 28374, 213, 3445, 3, 2, 1, 171893, 1383, 15026, 111, 77, 5, 1, 1043710445721, 3091, 74783, 201, 8718, 5, 8, 1

Offset

1,2

Comments

First two columns are A006558 and A113466. First four rows are A000012, A065559, A113467 and A113468. a(9, 1) is unknown; the rest of the 9th antidiagonal is 8129,88015,201,8718,5,8,3,1.

Links

Table of n, a(n) for n=1..36.

Example

a(4, 3) = 3445 because 3445, 3448, 3451 and 3454 each have 8 divisors.

Crossrefs

Cf. A006558, A065559, A113456, A113466, A113467, A113468.

Sequence in context: A081541 A344105 A323751 * A113456 A205445 A127608

Adjacent sequences: A113462 A113463 A113464 * A113466 A113467 A113468

Keyword

nonn,tabl,less

Author

David Wasserman, Jan 08 2006

Status

approved