A093488 Define the signature symmetry of a number n to be k if n-r and n+r have the same prime signature for r = 1 to k but not for k+1. Sequence contains the signature symmetry of n.

0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0

Offset

1,12

Comments

Subsidiary sequence: Index of the first occurrence of n in this sequence.

Links

Table of n, a(n) for n=1..105.

Example

a(12) = 2 as 11 and 13 are both prime 10 and 14 both have prime signature p*q but 9 and 15 have distinct prime signature.

Crossrefs

Cf. A093489, A093491, A093492.

Sequence in context: A252459 A083918 A083895 * A085858 A188172 A106671

Adjacent sequences: A093485 A093486 A093487 * A093489 A093490 A093491

Keyword

nonn

Author

Amarnath Murthy, Apr 16 2004

Extensions

More terms from Joshua Zucker, Jul 24 2006

Status

approved