68141

Properties

Appears in sequences

• a(1)=5, a(n) is the smallest prime dividing 4*Q^2 + 1 where Q is the product of all previous terms in the sequence.at n=20A057207
• Squares of the norms of Gaussian primes from A107632.at n=10A107633
• Primes p such that (5*p+2)/3 is the square of a prime.at n=18A357199
• a(n) = (2*n^3 - n^2 + 3*n - 2)/2.at n=40A363288
• a(n) is the smallest number which can be represented as the sum of two distinct nonzero octagonal numbers in exactly n ways, or -1 if no such number exists.at n=3A374143
• Second component B of the pairs (A, B) from A389379.at n=26A389390
• Prime numbersat n=6784