27742

Appears in sequences

• Coefficient of x^7 in expansion of (1+x+x^2)^n.at n=9A005715
• Expansion of (1+3*x^2+7*x^3+15*x^4+13*x^5+15*x^6+8*x^7+4*x^8)/((1-x)*(1-x^2)^3*(1-x^3)^2).at n=19A037241
• a(n) = a(1) + a(2) + ... + a(n-1) - a(m), where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = a(2) = 1 and a(3) = 2.at n=17A049889
• Expansion of (1+x^3*C^3)*C^4, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=8A071737
• Consider the smallest denominator q such that the Sylvester expansion of n/q has n terms. Here q has the form q = k*n+1 and we set a(n) = k.at n=24A098853
• Indices of primes in sequence defined by A(0) = 49, A(n) = 10*A(n-1) - 51 for n > 0.at n=18A101725
• a(n) = 1331*n - 209.at n=20A157444
• Number of side-2 hexagonal 0..n arrays with values nondecreasing E, SW and SE.at n=8A216938
• Irregular triangle read by rows: T(n,m) = number of lattice paths of type A^H terminating at point (n, m).at n=48A291081
• Triangle read by rows: T(n,k) (for 0 <= k <= floor(n/2)) is the number of permutations of length n that have k descents and avoid the patterns 321 and 2341.at n=52A304429
• Triangle read by rows T(n,k) is the number of diamond coverings for a specific number of diamonds covering an odd length row of triangles.at n=70A381552