66466

Appears in sequences

• Numbers having four 6's in base 10.at n=16A043516
• Decimal concatenations of the 38 quintuples (d1,d2,d3,d4,d5) with elements in {2,4,6} for which there exists a prime p >= 7 such that the differences between the 6 consecutive primes starting with p are (d1,d2,d3,d4,d5).at n=35A078870
• Palindromes in A005448.at n=4A162703
• Number of 5-element subsets of [n] whose sum is a triangular number.at n=38A320851
• a(n) = 6*(10^(2*n+1)-1)/9 - 2*10^n.at n=2A332164
• Centered triangular numbers which are products of three distinct primes.at n=33A359624