OFFSET
1,1
COMMENTS
A sequence with P=a(k) distinct numbers contains a subsequence of p=A127435(k) monotonically increasing or decreasing terms, according to a corollary of the Erdos-Szekeres theorem.
FORMULA
a(n) = (A127435(n)-1)^2 + 1.
MATHEMATICA
Select[(Prime@Range[300] - 1)^2 + 1, PrimeQ] (* Ray Chandler, Jan 23 2007 *)
PROG
(PARI) listp(nn) = {forprime(p=2, nn, if (isprime(q=(p-1)^2 + 1), print1(q, ", ")); ); } \\ Michel Marcus, Jun 08 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Jan 14 2007
EXTENSIONS
Corrected and extended by Ray Chandler, Jan 23 2007
STATUS
approved