45838

Appears in sequences

• Number of distinct nonzero absolute values of Sum_{j=1..n} sigma_j * exp(i * Pi * j / n) where sigma_j = +- 1.at n=21A013914
• Numbers n such that 107*2^n-1 is prime.at n=20A050579
• Number of regions in regular n-gon which are quadrilaterals (4-gons) when all its diagonals are drawn.at n=39A067151
• Number of permutations of [n] with exactly 2 descents which avoid the pattern 1324.at n=13A098992
• a(n) = Sum_{k=0..floor(3*n/11)} binomial(3*n-10*k,k).at n=23A392350