19041

Appears in sequences

• Pseudoprimes to base 35.at n=37A020163
• Integers n such that 10^n-17 is prime.at n=14A108326
• Let r be the matrix {{1,1},{0,1}} and b={{1,0},{1,0}}. Let A be the semigroup generated by r and b. a(n) is the number of words of length n in A.at n=40A121946
• Integers 1 through n written in primorial base, summed as if decimal.at n=39A122613
• Twin prime products minus 2.at n=10A124659
• Product of successive primes minus 2.at n=32A124669
• a(n) = n*(n^2 + 2*n - 1)/2.at n=32A127736
• Wiener index of the prism graph Y_n on 2n nodes.at n=32A138179
• G.f.: 1/(1-x-16*x^2).at n=7A168579
• Wiener index of the Moebius ladder M(n).at n=32A180857
• Centered 32-gonal numbers.at n=34A195315
• Right edge of the triangle A045975.at n=32A204557
• Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=6A207781
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=51A207785
• Number of 7Xn 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 0 and 1 0 1 vertically.at n=3A207789
• Number of directed 3-regular graphs on n nodes.at n=4A219890
• Number of directed 4-regular graphs on n nodes.at n=3A219891
• Number of (n+1) X (1+1) 0..1 arrays with every element equal to some horizontal, vertical or antidiagonal neighbor, with top left element zero.at n=7A232031
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every element equal to some horizontal, vertical or antidiagonal neighbor, with top left element zero.at n=28A232038
• T(n,k)=Number of (n+1)X(k+1) 0..1 arrays with every element equal to some horizontal, vertical or antidiagonal neighbor, with top left element zero.at n=35A232038