26384

Appears in sequences

• Triangle read by rows: T(n,k), n >=1, 0 <= k <= C(n,k), = number of n X n symmetric positive definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with k 1's above the diagonal.at n=84A080858
• Given the infinite continued fraction i+(i/(i+(i/(i+...)))), where i is the square root of (-1), this is the denominator of the real part of the convergents.at n=23A091807
• Triangle read by rows: T(n,k) = T(n-1,k-1) +T(n-1,k) +n*(n-1)*T(n-2,k-1) for n>4 and 1<=k<=n.at n=24A153592
• Number of non-equivalent ways to choose two points in an equilateral triangle grid of side n.at n=32A227327
• Numbers which are representable as a sum of seventeen but no fewer consecutive nonnegative integers.at n=37A270302
• Numbers k such that (238*10^k - 1)/3 is prime.at n=25A273542
• Coefficients in asymptotic expansion of sequence A275754.at n=7A289996
• a(n) = 2^n with 1's and 2's swapped.at n=14A306392
• The numbers 2^n with 1's and 2's swapped, then sorted.at n=14A323948