19117

Appears in sequences

• Numbers whose base-2 representation has exactly 13 runs.at n=21A043580
• a(n) = a(1) + a(2) + ... + a(n-1) + a(m) for n >= 4, where m = 2*n - 2 - 2^(p+1) and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 3.at n=13A049975
• Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 16 (most significant digit on right).at n=12A061969
• a(0)=1, a(1)=1, a(n)=7*a(n/2) for n=2,4,6,..., a(n)=6*a((n-1)/2)+a((n+1)/2) for n=3,5,7,....at n=42A116522
• a(n) = 15*n^2 - 9*n + 1.at n=36A134154
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>=x^2+y^2.at n=42A211636
• Number of arrays of maxima of three adjacent elements of some length 7 0..n array.at n=8A228462
• Numbers k such that (11*10^k - 113) / 3 is prime.at n=21A280557
• Numbers k such that k![4] - 256 is prime, where k![4] = A007662(k) = quadruple factorial.at n=36A329177