2,1

Euler polynomial is giving primes for consecutive x from 0 to 39.

Numbers x for which x^2 + x + 41 is not prime see A007634.

Composite numbers of the form x^2 + x + 41 see A145292.

Smallest x such that polynomial x2 + x + 41 have exactly n distinct prime divisors see A145293.

a(2)=40 because when x=40 than x^2+x+41=1681=41^2 a(3)=1721 because when x=1721 than x^2+x+41=2963603=43*41^3 a(4)=14144 because when x=14144 than x^2+x+41=200066921=41*47^4 a(5)=2294005 because when x=2294005 than x^2+x+41=5262461234071=35797*43^5

A005846, A007634, A145292, A145294, A145295

Sequence in context: A009984 A041761 A140702 this_sequence A147520 A143314 A060056

Adjacent sequences: A145291 A145292 A145293 this_sequence A145295 A145296 A145297

nonn

Artur Jasinski (grafix(AT)csl.pl), Oct 07 2008