42785

Appears in sequences

• Number of Twopins positions.at n=26A005689
• Number of partitions of n into parts not of the form 21k, 21k+8 or 21k-8. Also number of partitions with at most 7 parts of size 1 and differences between parts at distance 9 are greater than 1.at n=42A035986
• Diagonal sums of the triangular matrix A190088.at n=10A190090
• a(n) = Sum_{k=0..n} (-1)^k*C(n, k)^2*C(2*k, k), where C(n, k) denotes the binomial coefficient n!/(k!*(n-k)!).at n=9A244973
• p-INVERT of (1,0,0,1,0,0,1,0,0,...), where p(S) = (1 - S^2).at n=31A289918
• Expansion of (1 - x + x^3)/((1 - x + x^3)^2 - 4*x^3).at n=15A376717