23010

Appears in sequences

• Number of n-step mappings with 4 inputs.at n=20A005945
• Pseudo-random numbers: a (very weak) pseudo-random number generator from the second edition of the C book.at n=6A061364
• Self-convolution of A004148 (the RNA secondary structure numbers) with itself.at n=13A089735
• 33-gonal numbers: n(31n-29)/2.at n=39A098923
• First monotonically increasing sequence such that erasing the first and last digit of each term and concatenating what is left results in the concatenation of all terms of the sequence.at n=41A106004
• Triangle read by rows: T(n,k) (0 <= k <= ceiling(n/2)-1) is the number of (1,0) steps at level k in all peakless Motzkin paths of length n (can be easily translated into RNA secondary structure terminology).at n=49A110237
• Triangle Q, read by rows, such that Q^2 transforms column k of Q^2 into column k+1 of Q^2, so that column k of Q^2 equals column 0 of Q^(2*k+2), where Q^2 denotes the matrix square of Q.at n=31A113350
• Column 3 of triangle A113350, also equals column 0 of A113340^8.at n=4A113353
• Triangle, read by rows, given by the product Q^-1*P^2, where the triangular matrices involved are P = A113340 and Q = A113350.at n=40A113368
• Expansion of series reversion of x(1-7x)/(1-x).at n=4A131926
• 13 times hexagonal numbers: a(n) = 13*n*(2*n-1).at n=30A194713
• Number of nX7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=2A207716
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=38A207717
• Number of 3 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 1 0 0 vertically.at n=6A207718
• Number of nX7 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=2A208368
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=38A208369
• Numbers k such that k+1, 2k+1, 3k+1, 4k+1 are all prime.at n=9A237189