20612

Appears in sequences

• Number of (7+2) X (n+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.at n=25A252726
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 41", based on the 5-celled von Neumann neighborhood.at n=31A269874
• Numbers k such that A090086(k), the smallest pseudoprime to base k (not necessarily exceeding k), is a Carmichael number.at n=35A293203
• Numbers that are the sum of eight fourth powers in exactly eight ways.at n=24A345840
• G.f.: Sum_{k>=0} x^(k*(k+1)) * Product_{j=1..k} ((1 + x^j)/(1 - x^j))^2.at n=27A376852