13333333

Appears in sequences

• Number of Fibonacci numbers F(k), k <= 10^n, which end in 9.at n=7A073556
• Expansion of g.f. (1+2*x)/((1-x)*(1-10*x)).at n=7A097166
• a(n) = Sum_{k=0..n} C(floor((n+1)/2),floor((k+1)/2)) * 3^k.at n=14A097169
• Smallest semiprime containing exactly n 3's.at n=6A104685
• Smallest semiprime ending in exactly n 3's.at n=6A106658
• Numbers k such that the k-th triangular number contains only digits {1,8,9}.at n=18A119151
• a(n) = A133195(n)/3.at n=22A133201