141121

Properties

Appears in sequences

• Half-quartan primes: primes of the form p = (x^4 + y^4)/2.at n=31A002646
• Primes with digital product = 8.at n=12A107694
• Primes of the form 5k^2 + 1.at n=11A137530
• a(n) = n base 5, under morphism f(1) = 121, f(2) = 123, f(3) = 141, f(4) = 142, or 0 if n base 5 has a zero.at n=15A137850
• a(n) = number of zeros of the Mertens function M(x) in the interval 0 < x < 10^n (M(x) is the matching summatory function for the Moebius function).at n=8A171910
• A symmetrical triangle sequence:t(n,m)=(-1)^m*(n - m)!*Binomial[n - 1, m] + (-1)^(n - m + 1)*(n - (n - m + 1))!*Binomial[n - 1, n - m + 1].at n=21A176862
• A symmetrical triangle sequence:t(n,m)=(-1)^m*(n - m)!*Binomial[n - 1, m] + (-1)^(n - m + 1)*(n - (n - m + 1))!*Binomial[n - 1, n - m + 1].at n=27A176862
• Primes of the form 2520k + 1 for some k.at n=20A217588
• a(n) = n*(n+1)!/2 + 1.at n=7A300559
• Primes of the form (k+1)!*k/2 + 1.at n=6A302859
• Numbers k such that k divides the sum of digits in factorial base of all numbers from 1 to k.at n=30A333702
• Prime numbersat n=13106