A085075 Smallest number a(n) == -1 (mod n) such that the prime signature of n and a(n) is the same, or 0 if no such number exists.

3, 2, 0, 19, 35, 13, 343, 0, 39, 43, 275, 103, 55, 14, 0, 67, 539, 37, 99, 62, 21, 137, 2375, 49, 51, 4913, 279, 173, 2639, 61, 0, 65, 33, 34, 0, 73, 265, 38, 999, 163, 1595, 257, 175, 44, 91, 281, 29375, 0, 99, 203, 207, 211, 2375, 219, 783, 341, 57, 353, 14399, 487, 123

Offset: 2

Author

Amarnath Murthy, Jul 01 2003

Keywords

• nonn

Examples

			a(6) =35 = 6*6 -1 = 3*13 and 6 = 2*3 are both of prime signature p*q, where p and q are primes.
		

Crossrefs

Cf. A085074.

Extensions

More terms from David Wasserman, Jan 12 2005