OFFSET
1,12
COMMENTS
Number of odd solutions to phi(k) = prime(n) - 1, except k = prime(n).
REFERENCES
Alexander S. Karpenko, Lukasiewicz's Logics and Prime Numbers, Luniver Press, Beckington, 2006, pp. 52-56.
LINKS
Arkadiusz Wesolowski, Table of n, a(n) for n = 1..1000
CROSSREFS
KEYWORD
nonn
AUTHOR
Arkadiusz Wesolowski, Jan 20 2013
STATUS
approved