1333333

Appears in sequences

• Number of Fibonacci numbers F(k), k <= 10^n, which end in 9.at n=6A073556
• Expansion of g.f. (1+2*x)/((1-x)*(1-10*x)).at n=6A097166
• a(n) = Sum_{k=0..n} C(floor((n+1)/2),floor((k+1)/2)) * 3^k.at n=12A097169
• Numbers k such that the k-th triangular number contains only digits {1,8,9}.at n=17A119151
• a(n) = A133195(n)/3.at n=19A133201
• Minimum number k for which the digital sum of k*n is 4*n.at n=15A147824
• Minimum number k for which the digital sum of k*n is 10*n.at n=6A147830
• Mersenne primes written in base 4.at n=4A161677
• Fermat pseudoprimes to base 2 of the form (n^2 + 2*n)/3.at n=26A216170
• Fermat pseudoprimes to base 2 that are octagonal.at n=26A321868
• Starting from 1, successively take the smallest "Choix de Bruxelles" with factor 13 which is not already in the sequence.at n=6A360190