133333

Appears in sequences

• Number of Fibonacci numbers F(k), k <= 10^n, which end in 9.at n=5A073556
• Expansion of g.f. (1+2*x)/((1-x)*(1-10*x)).at n=5A097166
• a(n) = Sum_{k=0..n} C(floor((n+1)/2),floor((k+1)/2)) * 3^k.at n=10A097169
• Smallest semiprime containing exactly n 3's.at n=4A104685
• Near-repdigit semiprimes with 3 as repeated digit.at n=38A105984
• Smallest semiprime ending in exactly n 3's.at n=4A106658
• Numbers k such that the k-th triangular number contains only digits {1,8,9}.at n=12A119151
• a(n) = A133195(n)/3.at n=16A133201
• Pseudoprimes to base 4, written in base 4.at n=18A262101
• Starting from 1, successively take the smallest "Choix de Bruxelles" with factor 13 which is not already in the sequence.at n=5A360190
• a(n) = Sum_{k=0..n} 2^k * binomial(4*n,k) * binomial(4*n-k-1,n-k).at n=4A386719