OFFSET
1,1
REFERENCES
David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See entry 496 at p. 155.
EXAMPLE
MATHEMATICA
Select[Range[600], PrimeQ[#]&&!PrimeQ[t=#(#+1)/2+1]&&!PrimeQ[t-3] &]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Stefano Spezia, Sep 15 2024
STATUS
approved