21807

Appears in sequences

• Number of 3's in all partitions of n.at n=35A024787
• Numbers n such that the sum of the squares of the digits of n^n is a square.at n=23A171976
• Numbers k such that 44*10^k + 3 is prime.at n=21A291606
• Weighted count of equivalence classes of words w of length n+3 over {a, b, c, d, A, *} having exactly n letters, exactly three *'s, an even number of lowercase a's, and weight (-1)^(A(w)), where A(w) is the number of uppercase letters A.at n=5A390530