OFFSET
1,4
LINKS
Michel Lagneau, Table of n, a(n) for n = 1..10000
EXAMPLE
MAPLE
i:=0:for n from 2 to 1000 do:x:=n^2+1:if type (x, prime)=true then printf(`%d, `, i):i:=0:else i:=i+1:fi:od:
MATHEMATICA
cfn2[{a_, b_}]:=Count[Range[a+1, b-1], _?(IntegerQ[Sqrt[#-1]]&)]; cfn2/@ Partition[ Select[Prime[Range[50000]], IntegerQ[Sqrt[#-1]]&], 2, 1] (* Harvey P. Dale, Jan 13 2019 *)
PROG
(PARI) c=0; for(n=2, 1e9, !ispseudoprime(n^2+1) & c++ & next; print1(c", "); c=0) \\ M. F. Hasler, Feb 07 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, Feb 07 2012
STATUS
approved