20456

Appears in sequences

• Numbers that are the sum of 11 positive 8th powers.at n=36A003389
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 71.at n=33A031569
• Number of step cyclic shifted sequence structures using exactly three different symbols.at n=14A056435
• McKay-Thompson series of class 16A for Monster.at n=18A058514
• Numbers k such that prime(k) == 1 (mod sigma(k)).at n=12A067697
• Numbers n such that p(n),p(n)+6,p(n)+12,p(n)+18 are consecutive primes and p(n)=6*k+1 for some k, where p(n) denotes n-th prime.at n=32A090838
• Expansion of (chi(q)^4 / chi(-q))^2 in powers of q where chi() is a Ramanujan theta function.at n=9A143895
• (A192533)/2.at n=34A192534
• Numbers k such that 2*(3^k-2*k)+1 is prime.at n=13A195815
• Number of n X 4 0..1 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.at n=14A223834
• Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 7.at n=48A240016
• a(n) is the index of the first occurrence of the Euclidean distance prime(n) from a point on a square spiral to its starting point at 1.at n=24A336335
• Irregular triangle read by rows: the right-hand side of the triangle in A349815.at n=74A349816
• Numbers k for which phi(k) = phi(k''), where phi is the Euler totient function (A000010) and k'' the second arithmetic derivative of k (A068346).at n=36A352331
• Indices of records in A361321.at n=45A361326