18483

Appears in sequences

• a(n) = [ a(n-1)/a(1) + a(n-3)/a(3) + a(n-5)/a(5) + ... ], for n >= 3.at n=39A022871
• a(n) = Sum_{k=0..n} binomial(n,k)*binomial(2*k,k).at n=7A026375
• a(n) = T(n,[ n/2 ]), where T is the array in A026374.at n=13A026380
• Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 13 ones.at n=34A031781
• Starting positions of strings of three 8's in the decimal expansion of Pi.at n=13A083637
• Numbers n such that (n+j) mod (2+j) = 1 for j from 0 to 6 and (n+7) mod 9 <> 1.at n=14A096025
• Riordan array (1/sqrt(1-6x+5x^2),(1-3x-sqrt(1-6x+5x^2))/(2x)).at n=28A110165
• Triangle read by rows: T(n,k) (0<=k<=floor(n/2)) is the number of Delannoy paths of length n, having k ED's.at n=16A110221
• Riordan array (1/sqrt(1-6x+5x^2),x/(1-6x+5x^2)).at n=28A111965
• Triangle interpolating the swinging factorial (A056040) restricted to even indices with its binomial transform. Same as interpolating bilateral Schroeder paths (A026375) with the central binomial coefficients (A000984).at n=28A163841
• T(n,k)=Number of length n+k 0..2 arrays with at most two downsteps in every k consecutive neighbor pairs.at n=37A255622
• Number of length n+2 0..2 arrays with at most two downsteps in every n consecutive neighbor pairs.at n=7A255624
• Expansion of Product_{k>=1} ((1 + x^k) * (1 + 2*x^k)).at n=22A266819
• Triangle read by rows, T(n,k) = GegenbauerC(m,-n,-3/2) where m = k if k<n else 2*n-k, for n>=0 and 0<=k<=2n.at n=56A272866
• Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(k*x)*BesselI(0,2*x).at n=62A292627
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) is Sum_{i=0..n} binomial(n,i)*Sum_{j=0..i} binomial(i,j)^k.at n=52A328807
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = Sum_{j=0..n} k^j * binomial(n,j) * binomial(2*j,j).at n=43A340970
• Number of branching factorizations of the least integer of each prime signature (A025487).at n=27A366884
• Number of distinct, irreducible ways that a Pythagorean hyperrectangle of 2 or more dimensions can produce diagonal length n.at n=50A375338