379721

Properties

Appears in sequences

• a(1) = 1; for n>1, a(n) = the largest prime divisor of the number C(n) formed from the concatenation of n, n-1, n-2, n-3, ... down to 1.at n=8A075021
• a(1) = 1, a(n) = the largest prime divisor of A138793(n).at n=8A138963
• Sequence is obtained from Catalan numbers (A000108) by taking the factorial of each digit and adding them up.at n=28A165163
• Largest prime factor of n^n - n^(n-1) - n^(n-2) - ... - n^2 - n - 1.at n=7A191624
• Let v = list of denominators of Farey series of order n (see A006843); let b(n) = Sum 1/(k*k'*(k+k')), where (k,k') are pairs of successive terms of v; a(n) = numerator of b(n).at n=10A278047
• Prime numbersat n=32277