268182

Appears in sequences

• Pentagonal numbers > 0 which are not the difference of two other pentagonal numbers > 0.at n=22A135769
• Pentagonal numbers > 0 which are not the difference of two larger pentagonal numbers.at n=33A136113
• a(n) = 2*a(n-1) - a(n-2) + 2*a(n-4) - a(n-5) + a(n-7) - a(n-8) - a(n-10) for n >= 10, where a(0) = 2, a(1) = 4, a(2) = 7, a(3) = 11, a(4) = 18, a(5) = 31, a(6) = 52, a(7) = 89, a(9) = 151, a(9) = 257.at n=22A289004