39817

Appears in sequences

• Strong pseudoprimes to base 18.at n=21A020244
• Cupolar numbers: a(n) = (n+1)*(5*n^2 + 7*n + 3)/3.at n=28A096000
• a(n) = (n^3 + 3*n - 2)/2.at n=42A132127
• Number of permutations of [n] having no substring [k,k+1,k+2,k+3].at n=8A132647
• G.f. satisfies: A(x) = Sum_{n>=0} x^n*A(x)^(n^5).at n=5A191807
• Wiener index of a benzenoid consisting of a double-step spiral chain of n hexagons (n>=2, s=21; see the Gutman et al. reference).at n=18A193397
• 100-gonal numbers: a(n) = 98*n*(n-1)/2 + n.at n=29A261276