30681

Appears in sequences

• Coefficient of x^4 in expansion of (1+x+x^2)^n.at n=26A005712
• a(n) is the number of binary strings of length n such that there exist 3 or more ones in a subsequence of length 5 or less.at n=14A131283
• a(n) = 58*n^2 - 1.at n=22A158668
• A triangle of polynomial coefficients:p(x,n)=Sum[(k + 1)^n*Binomial[x, k], {k, 0, Infinity}]/2^(x - n).at n=50A176667
• 1/6 the number of (n+2)X5 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.at n=3A184471
• 1/6 the number of (n+2)X6 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.at n=2A184472
• T(n,k)=1/6 the number of (n+2)X(k+2) 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.at n=17A184477
• T(n,k)=1/6 the number of (n+2)X(k+2) 0..2 arrays with each 3X3 subblock containing one of one value, four of another, and four of the last.at n=18A184477
• Triangle read by rows, T(n,k) = Sum_{j=0..n} (-1)^(n-j)*C(-j,-n)*S1(j,k), S1 the Stirling cycle numbers A132393, for n>=0 and 0<=k<=n.at n=39A269951
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n), where a(0) = 2, a(1) = 4, b(0) = 1, b(1) = 3, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A296297
• a(n) = trinomial(2*n, 4) = (1/6)*n*(2*n - 1)*(2*n^2 + 7*n - 3).at n=14A302710
• Numbers k such that 465*2^k+1 is prime.at n=36A318193
• Triangle read by rows: T(n,k) is the coefficient of x^k in the ZZ polynomial of the hexagonal graphene flake O(3,3,n).at n=32A338158
• Expansion of e.g.f. log(1-x)^2 * exp(x) / (2 * (1-x)).at n=7A381024