81517

Properties

Appears in sequences

• From table of maximal epacts e(p) and corresponding primes p, for x_1=2, x_{m+1} = (x_m)^2+1; sequence gives p.at n=40A014424
• Concatenation of primitive Pythagorean triangles, sorted.at n=3A138043
• Primes formed from the concatenation of primitive Pythagorean triples.at n=0A138044
• Primes p of the form p=n^2+3n+9 such that q=p^2+3p+9 is also prime.at n=7A175284
• One-quarter of the number of regions in the central square of an equal-armed cross with arms of length n (as in A331456).at n=16A337641
• Primes of the form prime(i)*prime(i+1)+prime(i+2)*prime(i+3)+...+prime(k-1)*prime(k).at n=22A340465
• Prime numbersat n=7972