26146

Appears in sequences

• Number of difference sets of subsets of {1,2,...,n}, i.e., the size of {D(A) : A subset [n] }, where D(A)={a_i-a_j : a_i>a_j and a_i,a_j in A}.at n=21A067247
• a(n) = Min{x : A073124(x) = 2n}.at n=46A096480
• Numbers k for which 16*k+1, 16*k+3, 16*k+7, 16*k+13 and 16*k+15 are primes.at n=4A123990
• Maximal length of rook tour on an n X n+4 board.at n=31A152135
• Number of strings of numbers x(i=1..n) in 0..6 with sum i*x(i) equal to n*6.at n=8A184700
• Number of strings of numbers x(i=1..9) in 0..n with sum i*x(i) equal to n*9.at n=5A184709
• Triangle of coefficients of polynomials v(n,x) jointly generated with A209141; see the Formula section.at n=49A209142
• Triangle of coefficients of polynomials v(n,x) jointly generated with A209745; see the Formula section.at n=50A209746
• Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal or vertical neighbor, and containing the value n(n+1)/2-2.at n=20A211905
• Beach-Williams Pell numbers of type 2pq (p,q primes).at n=4A212075
• Number of nondecreasing -n..n vectors of length 4 whose dot product with some nonincreasing -n..n vector equals 4.at n=12A226401
• Numbers n such that prime(n) + reversal(prime(n)) is a square.at n=13A227371
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 203", based on the 5-celled von Neumann neighborhood.at n=33A270727
• Index of first occurrence of n appearing twice in succession in van Eck's sequence (A181391), or 0 if it never occurs.at n=29A308782
• Irregular triangle read by rows: T(n,k) is the number of n X n tic-tac-toe positions (up to rotation and reflection) with k tokens (i.e., after k plays) which allow a winning strategy for X (n > 0, 0 <= k <= n^2).at n=30A317573