39401

Appears in sequences

• Denominators of continued fraction convergents to sqrt(98).at n=9A041177
• Denominators of continued fraction convergents to sqrt(392).at n=9A041745
• Denominators of continued fraction convergents to sqrt(882).at n=9A042705
• Pell equation solutions (7*a(n))^2 - 2*(5*b(n))^2 = -1 with b(n):=A097733(n), n >= 0. Note that D=50=2*5^2 is not squarefree.at n=2A097732
• p^2-p-1 that is not prime, where p is prime.at n=26A119609
• Maximal non-semiprime number which is a "preprime" of the n-th kind (defined in comment in A247395).at n=34A247834
• a(n) = (prime(1+n)*prime(n)) + prime(n) + 1.at n=44A286624
• a(n) = (p_n + 1)*q_n - 1; where (p_n, q_n) is the n-th twin prime pair.at n=14A328493
• Triangle T(n,k), n >= 2, 0 <= k <= floor(n^2/2)-n, read by rows, where T(n,k) is the number of 2*(k+n)-cycles in the n X n grid graph which pass through NW and SW corners.at n=23A333652
• Smallest number k with A355915(k) = n.at n=39A356792
• Greatest positive integer whose weakly increasing prime indices have zero-based weighted sum (A359674) equal to n.at n=36A359757