30947

Appears in sequences

• Numbers k such that k^2+k+3 is a palindrome.at n=16A027714
• Number of n X n binary arrays symmetric under horizontal reflection with all ones connected only in a 1010-1111-0100 pattern in any orientation.at n=11A146635
• Number of primes of the form x^4 + 1 less than 10^n.at n=22A214452
• Number of nonempty pairwise coprime subsets of {1,...,n}, where a single number is not considered to be pairwise coprime unless it is equal to 1.at n=28A320426
• a(n) is the number whose base-4 digits are 1 followed by the first n-1 terms of the periodic sequence with initial period 3,2,0.at n=7A378502