19605

Appears in sequences

• a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Fibonacci numbers), t = (odd natural numbers).at n=25A025083
• Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 56.at n=4A031734
• Numbers n such that 291*2^n-1 is prime.at n=25A050904
• Total number of elements in all primitive subsets of the integers 1 to n.at n=18A087077
• 47-gonal numbers.at n=29A095311
• Table with g.f. [1-x*n-sqrt(x^2*n^2-2*n*x+1+4*x^2-4*x)]/(2*x).at n=60A128888
• a(n+1)-+a(n)=prime, a(n+1)*a(n)=Average of twin prime pairs, a(1)=3,a(2)=10.at n=30A154496
• a(n) = 676*n + 1.at n=28A158386
• a(n) = 25*n^2 + 5.at n=27A158445
• Number of (w,x,y,z) with all terms in {1,...,n} and 3w=x+y+z+n.at n=36A212247
• Number of (2+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=25A250757
• T(n,k)=Number of nXk arrays containing k copies of 0..n-1 with no element 1 greater than its north, west or northwest neighbor modulo n and the upper left element equal to 0.at n=31A266832
• Number of 4Xn arrays containing n copies of 0..4-1 with no element 1 greater than its north, west or northwest neighbor modulo 4 and the upper left element equal to 0.at n=4A266834
• Expansion of Product_{k>=1} (Product_{j=1..k} (1 + x^(k*j))^(k*j)).at n=17A327065