126861

Appears in sequences

• a(n) = floor( binomial(n,7)/7 ).at n=27A011853
• Generalized Catalan numbers C(-10; n).at n=5A064332
• Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.at n=6A180789
• Number of (n+1)X7 0..3 arrays with every 2X2 subblock having nonzero determinant and commuting with every horizontal or vertical neighbor.at n=9A206341
• a(n) = 1/7*( binomial(n,7) - floor(n/7) ).at n=19A215053
• Numbers k such that 371*2^k+1 is prime.at n=30A323010