18272

Appears in sequences

• Restricted permutations.at n=15A000496
• a(n) = 2*(a(n-1) + a(n-2)), a(0) = 0, a(1) = 1.at n=11A002605
• Seidel's triangle, read by rows.at n=43A014781
• Number of ordered quadruples of integers from [ 2,n ] with no global factor.at n=24A015638
• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 67.at n=35A031565
• a(n)*a(n+3) - a(n+1)*a(n+2) = 2^n, given a(0)=1, a(1)=1, a(2)=6.at n=10A080879
• Numbers n such that n, n+1, n+2, n+3, n+4 are all of the form x^2+2*y^2 for nonnegative x, y.at n=11A096783
• Triangle read by rows: Each row is constructed by forming the partial sums of the previous row, reading from the right and at every other row repeating the final term.at n=43A099959
• a(n) = Sum_{k=0..n} binomial(2n+1, 2k)*3^(n-k).at n=5A102591
• Sylvester cyclotomic numbers for A002605.at n=10A105607
• Leftmost node in rows of the power tree A114622.at n=18A114625
• Sequence arising from the factorization of F(n)=A002605 and L(n)=A080040 F(0)=0, F(1)=1, F(n)=2*F(n-1)+2*F(n-2), L(0)=2, L(1)=2, L(n)=2*L(n-1)+2*L(n-2).at n=21A127259
• a(n) = 2*a(n-1)+6*a(n-2) for n>=3, a(0)=1, a(1)=2, a(2)=8.at n=8A133592
• Expansion of g.f.: x^2*(1 + x - x^2)/(1 - 2*x^2 - 2*x^4).at n=22A160444
• Elements of A160444, pairs of consecutive entries swapped.at n=23A160572
• Triangle read by rows: T(n,k) is the number of 2-compositions of n having k even entries (0<=k<=n).at n=65A181297
• Number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of x(i)*x(i+1) equal to zero.at n=28A188250
• E.g.f.: A(x) = 1/(1 - 6*x^2)^(1 + 1/(3*x)).at n=5A193289
• Triangle of coefficients of polynomials u(n,x) jointly generated with A208760; see the Formula section.at n=65A208759
• Number of standard Young tableaux of n cells and height >= 5.at n=6A218265