A113456 Square array read by antidiagonals: a(n, d) is the smallest number that begins an arithmetic progression with common difference d of n numbers with the same prime signature.

1, 2, 1, 33, 3, 1, 19940, 3, 2, 1, 204323, 213, 155, 3, 1, 380480345, 213, 7572, 3, 2, 1

Offset: 1

Author

David Wasserman, Jan 08 2006; corrected Jan 08 2006

Keywords

• nonn
• tabl
• less

Comments

First two columns are A034173 and A113457. First three rows are A000012, A086489 and A113458.

Examples

			a(3, 2) = 3 because 3, 5 and 7 have the same prime signature.