151169

Properties

Appears in sequences

• a(n) = Sum_{k=0..n} C(n-k,3k).at n=22A003522
• Expansion of log(1+tan(x))*exp(x).at n=9A009371
• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 31.at n=19A031619
• a(n) is the least prime p, such that next_prime(2*p) - 2*p = 2*n - 1.at n=30A059846
• Number of compositions of n such that two adjacent parts are not equal modulo 2.at n=31A062200
• Primes p such that 128p+1 and (p-1)/128 are both prime.at n=3A086477
• Numbers which form a prime by appending a 3-digit number and form no primes by appending 1 digit or 2 digits.at n=25A365813
• a(n) = Sum_{k=0..floor(n/2)} binomial(2*n-k,3*k).at n=11A392400
• Prime numbersat n=13947