OFFSET
1,1
COMMENTS
a(n) = 0 for prime n > 2.
EXAMPLE
a(14) = 23 as 23-1 = 22 = 11*2 has the same prime signature p*q, 14 = 2*7.
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Apr 01 2004
EXTENSIONS
Corrected and extended by Rick L. Shepherd, Jun 17 2004
STATUS
approved