A165501 Minimal common difference of maximal arithmetic progression starting at n such that each term k has tau(k)=tau(n).

1, 2, 5, 6, 2, 150, 19, 16, 12, 1536160080, 8, 9918821194590, 300, 188, 65, 341976204789992332560, 157, 2166703103992332274919550, 24, 450, 3072320160

Offset: 2

Author

Hugo van der Sanden, Sep 21 2009, Oct 09 2009

Keywords

• hard
• nonn
• more

Comments

a(1) is not well defined, since the maximal progression has only one term.

Examples

			For n=6, A165500(n)=3, and the least difference d such that tau(6) = tau(6+d) = tau(6+2d) is d=2, so a(6)=2.
		

Crossrefs

Cf. A165499, A165500, A088430.

Extensions

Extended to n=22 taking advantage of A088430 for n=19, Hugo van der Sanden, Jun 02 2015