374166

Appears in sequences

• a(n)/100000 gives sqrt(n) to 5 places after the decimal point.at n=13A027663
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k doubledescents (0 <= k <= n-2). We say that i is a doubledescent (also called a double fall) of a permutation p if p(i) > p(i+1) > p(i+2).at n=41A162975
• Number of (n+1) X (2+1) 0..3 arrays with every 2 X 2 subblock summing to 6 and no 2 X 2 subblock having exactly two nonzero entries.at n=8A251230
• Number of permutations of [n] having exactly three (possibly overlapping) doubledescents.at n=5A279292