28681

Appears in sequences

• a(n) = b(n) + d(n), where b(n) = (n-th Fibonacci number > 2 ) and d(n) = (n-th number that is 1, 2, or 3, or is not a Lucas number).at n=19A023502
• Dirichlet convolution of Fibonacci numbers with sigma(n).at n=22A034747
• Expansion of (1-x)^(-1)/(1-2*x^2+x^3).at n=24A077880
• Counterexamples to the conjecture that an even, prime-indexed triangular plus 1 equals a prime or that an odd, prime-indexed triangular minus 2 equals a prime.at n=19A097785
• Odd numbers n for which 19 is the smallest i (>= 1) with Jacobi symbol J(i,n) getting either a value 0 or -1.at n=13A112078
• Number of diagonal rectangles with corners on an n X n grid of points.at n=18A113751
• Initial term of a series of exactly n consecutive non-Niven (or Harshad) numbers.at n=28A144378
• Number of n X 6 0..3 arrays with row sums 6 and column sums n.at n=2A172738
• Number of n X 3 0..3 arrays with row sums 3 and column sums n.at n=5A172743
• Number of 2*n X n 0..3 arrays with row sums 3 and column sums 6.at n=2A172753
• Number of 2*n X n 0..3 arrays with row sums 6 and column sums 12.at n=2A172755
• Number of 2*n X n 0..3 arrays with row sums n and column sums 2*n.at n=2A172762
• Number of n X 6 0..4 arrays with row sums 6 and column sums n.at n=2A172814
• Number of 2*n X n 0..4 arrays with row sums 9 and column sums 18.at n=2A172827
• Number of n X 6 0..5 arrays with row sums 6 and column sums n.at n=2A172865
• Number of n X 6 0..6 arrays with row sums 6 and column sums n.at n=2A172904
• Number of nX7 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=3A208163
• T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=48A208164
• Number of 4Xn 0..1 arrays avoiding 0 0 0 and 1 0 1 horizontally and 0 0 1 and 0 1 0 vertically.at n=6A208165
• Positions of 2 in sequence A217916.at n=32A217918