64420

Appears in sequences

• a(n) in base 11 is a repdigit.at n=44A048335
• Successively larger gaps in Ulam numbers start at this Ulam number.at n=19A080287
• Number of unlabeled mating graphs with n nodes and a degenerate adjacency matrix.at n=8A133279
• Number of (n+2) X 9 0..1 matrices with each 3 X 3 subblock idempotent.at n=17A224558
• a(n) = least positive integer m such that m*(m+1) has n-2 distinct digits in base n, all distinct from those (base-n digits) of m and m+1.at n=9A381248