19006

Appears in sequences

• Pseudoprimes to base 35.at n=36A020163
• Expansion of (1+x*C)*C^3, where C = (1-sqrt(1-4*x))/(2*x) is g.f. for Catalan numbers, A000108.at n=8A070031
• Inverse of binomial transform of Whitney triangle.at n=46A097761
• a(n) = prime(x) - pi(x) where x is the least x such that (prime(x+1) - pi(x+1)) - (prime(x) - pi(x)) = n.at n=39A111183
• Number of unordered ways of making change for n dollars using coins of denominations 1, 5, 10, and 25.at n=5A160551
• Triangle read by rows: T(n,0) = (n+1)^2, T(n,k) = T(n,k-1) + T(n-1,k) for 0 < k < n, and T(n,n) = T(n,n-1).at n=43A165996
• Triangle read by rows: T(n,0) = (n+1)^2, T(n,k) = T(n,k-1) + T(n-1,k) for 0 < k < n, and T(n,n) = T(n,n-1).at n=44A165996
• a(n) is the smallest term m in A173978 for which A020639(2m-3) = prime(n), n > 1.at n=41A173980
• a(1) = 1; a(2*n) = prime(n)*a(n), a(2*n+1) = prime(n)*a(n) + a(n+1), where prime(n) is the n-th prime.at n=27A176716
• a(n) = Sum_{k=0..n} binomial(2*k,k)/(k+1)*binomial(2*n-1,n-k).at n=7A279013
• Anagrasum integers: integers N that exactly reproduce their set of digits when we form the set of sums of pairs of adjacent digits.at n=41A296521
• Number of n X 4 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=6A299802
• Number of nX7 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=3A299805
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=48A299806
• T(n,k)=Number of nXk 0..1 arrays with every element equal to 0, 1, 2, 4, 5, 6 or 8 king-move adjacent elements, with upper left element zero.at n=51A299806
• Number of squares and rectangles in the interior of the square with vertices (n,0), (0,n), (-n,0) and (0,-n) in a square (x,y)-grid.at n=12A330805
• a(n) = n * (binomial(n,2) - 2).at n=34A341768
• a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(2*n-2*k-1,n-2*k).at n=9A371798