106762

Appears in sequences

• a(n) = 2^(2*n+1) - binomial(2*n+1, n+1).at n=8A000346
• Chvatal conjecture for radius of graph of maximal intersecting sets.at n=18A007008
• a(n) = Sum_{k=0..8} binomial(n,k).at n=18A008861
• a(n) = 2^n - C(n,0)- ... - C(n,9).at n=18A035042
• a(n) = 2^n - binomial(n, floor(n/2)).at n=17A045621
• A triangle related to A000108 (Catalan) and A000302 (powers of 4).at n=46A046527
• a(n) = 2^(n-1) - ((1+(-1)^n)/4)*binomial(n, n/2).at n=18A058622
• Number of different positive integers that we can obtain from the integers {1,2,...,n} using each number at most once and the operators +, -, *, /, where intermediate subexpressions must be integers.at n=8A071603
• Triangle T(n,k), 0<=k<=n, read by rows; given by [0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, ...] DELTA [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ...] where DELTA is the operator defined in A084938.at n=64A094456
• Riordan array (1/sqrt(1-4*x), (1/sqrt(1-4*x)-1)/2).at n=46A116395
• Riordan matrix (1/(1-4x),(1-sqrt(1-4x))/2).at n=46A187926
• Number of horizontal segments in all dispersed Dyck paths of length n (i.e., in all Motzkin paths of length n with no (1,0)-steps at positive heights; a horizontal segment is a maximal sequence of consecutive (1,0)-steps).at n=18A191391
• T(n,k)=Number of binary arrays of length n+2*k-1 with fewer than k ones in any length 2k subsequence (=less than 50% duty cycle).at n=36A213118
• Triangle read by rows: T(n,g) is the number of rooted maps with n edges and 2 faces on an orientable surface of genus g.at n=20A270406
• Expansion of 1/(1 - Sum_{k>=1} mu(2*k-1)^2*x^(2*k-1)), where mu() is the Moebius function (A008683).at n=26A280198
• a(n) = 2^(n-1) + ((1+(-1)^n)/4)*binomial(n, n/2) - binomial(n, floor(n/2)).at n=18A294175