27838

Appears in sequences

• Numbers k such that 223*2^k+1 is prime.at n=28A032488
• a(n) = 9 + floor( Sum_{j=1..n-1} a(j)/3 ).at n=28A120154
• a(1)=1, a(n) = a(n-1) + n^4 if n odd, a(n) = a(n-1) + n^3 if n is even.at n=11A140160
• Number of acute triangles, distinct up to congruence, on an n X n grid (or geoboard).at n=26A190021
• n*(n^2-2*n-1).at n=30A214446
• Expansion of e.g.f. 1/( 1 - (1 + x) * log(1 + x) ).at n=7A362911