21095

Appears in sequences

• Number of solutions to c(1)*prime(4) + ... + c(n)*prime(n+3) = 2, where c(i) = +-1 for i > 1, c(1) = 1.at n=23A022920
• Number of binary words of length n containing at least one subword 10^{6}1 and no subwords 10^{i}1 with i<6.at n=44A143286
• Number of (n+2) X 6 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..1 introduced in row major order.at n=16A204377
• Numbers n such that numbers 30(n+k) + 1 are prime for k=0..5.at n=6A284659
• Number of function calls of the second kind required to compute ack(3,n), where ack denotes the Ackermann function.at n=5A304371
• Number of integer partitions of n containing all prime indices of their parts.at n=44A324753
• Triangle read by rows: T(n,k) = A(k,n-k), 1 <= k < n, 2 <= n, where A(m,n) is the number of distinct strings consisting of one X, 2*m Y's and 2*n Z's in which the X lies to the right of at least m Y's and at least n Z's.at n=17A351584
• Triangle read by rows: T(n,k) = A(k,n-k), 1 <= k < n, 2 <= n, where A(m,n) is the number of distinct strings consisting of one X, 2*m Y's and 2*n Z's in which the X lies to the right of at least m Y's and at least n Z's.at n=18A351584