18383

Appears in sequences

• Numbers n such that 103*2^n-1 is prime.at n=20A050577
• a(1) = 1+2-3 = 0, a(2) = 4+5+6-7 = 8, a(3) = 8+9+10+11-12 = 26, a(4) = 13+14+15+16+17-18 = 57, ...at n=31A111694
• a(n) = pq + pr + qr with p = prime(n), q = prime(n+1), and r = prime(n+2).at n=20A127345
• Composites in A127345.at n=10A127347
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, -1, 1), (0, 1, -1), (1, 0, 1), (1, 1, 1)}.at n=7A151001
• Number of partitions of n into exactly 4 different parts with distinct multiplicities.at n=38A212115
• Numbers n such that T(n) + T(n+1) + ... + T(n+21) is a square, where T(m) = A000217(m) is the m-th triangular number.at n=4A254443
• Somos's sequence {a(9,n)} defined in comment in A018896: a(0)= a(1) = ... = a(19) = 1; for n >= 20, a(n) = (a(n-1)*a(n-19) + a(n-10)^2)/a(n-20).at n=46A271839
• Denominator of harmonic mean of 3 consecutive primes. Numerators are A331259.at n=20A331260
• Numbers k of the form (x + y)*(x^2 + y^2) such that (x + y) and (x^2 + y^2) are primes.at n=30A349202