309760

Appears in sequences

• Number of (n+2) X (n+2) 0..1 arrays with no 3 X 3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 0 or 3 and no column sum 0 or 3.at n=23A258958
• Irregular triangle T(n,k) read by rows in which n-th row lists in colex order all series-reduced tree degree sequences D of n nodes encoded as t = Product_{d in D} prime(d); n >= 4, 1 <= k <= A002865(n-2).at n=36A345970
• Product_{n>=1} (1 + a(n)*x^n/n!) = 1 + tan(x).at n=8A353611
• Product_{n>=1} 1 / (1 - a(n)*x^n/n!) = 1 + tan(x).at n=8A353911
• a(n) = coefficient of x^n*y^(n+1)/n! in (1/4) * log( Sum_{n>=0} (n + 2*y)^(2*n) * x^n/n! ).at n=4A359926