OFFSET
1,1
REFERENCES
M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988.
Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997.
LINKS
Daniel Starodubtsev, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = 2*A091271(n).
MATHEMATICA
Select[Range[4, 1200], PrimeQ[#^2-11]&] (* Vladimir Joseph Stephan Orlovsky, Feb 27 2011*)
CROSSREFS
KEYWORD
nonn
AUTHOR
Giovanni Teofilatto, Dec 20 2003
EXTENSIONS
Extended by Ray Chandler, Dec 27 2003
STATUS
approved