19852

Appears in sequences

• Numbers k such that the product of the digits of k is equal to the sum of the prime factors of k, counted with multiplicity.at n=35A065774
• Number of ordered trees with n edges and having no root-to-leaf branches.at n=11A082989
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n having k pyramids.at n=66A094322
• Triangle read by rows: T(n,k) is the number of Dyck paths of semilength n and having sum of pyramid heights equal to k.at n=66A094449
• Write 0, 1, ..., n in base 3 and add as if they were decimal numbers.at n=42A121718
• Square array of coefficients in the successive iterations of x*C(x) = (1-sqrt(1-4*x))/2 where C(x) is the g.f. of the Catalan numbers (A000108); read by antidiagonals.at n=60A158825
• Main diagonal in the array A158825 of coefficients of successive iterations of x*C(x), where C(x) is the Catalan function (A000108).at n=5A158832
• Numbers n such that d(n-2) = d(n) = d(n+2) = 12 where d(n)=A000005(n).at n=16A190645
• Ulam numbers k such that 4*k and 16*k are also Ulam numbers.at n=29A287634
• Number of compositions (ordered partitions) of n into heptagonal numbers (A000566).at n=46A322799
• Records of A058249: (Smallest prime >= 2^n) - (largest prime <= 2^n).at n=40A331620