27693

Appears in sequences

• From a problem in AI planning: a(n) = 4+a(n-1)+a(n-2)+a(n-3)+a(n-4)-a(n-5)-a(n-6)-a(n-7), n>7.at n=16A007800
• Indices of hexagonal numbers that are also pentagonal.at n=2A046179
• Largest eigenvalue, rounded to the nearest integer, of a rank n matrix of 1..n^2 filled successively along rows.at n=37A072333
• Numbers n such that 2*10^n + 3 is prime.at n=20A081677
• Sum of binary digits of all primes < 2^n, i.e., with at most n binary digits.at n=14A168155
• a(n) = (n + 1)*(4*n^2 + 14*n + 9)/3.at n=26A268484
• Indices of triangular numbers in A276914 which are also pentagonal.at n=5A276915
• a(n) = Sum_{k=0..floor(n/3)} binomial(3*n-3*k+1,n-3*k).at n=6A390703