20169

Appears in sequences

• Composite numbers whose prime factors contain no digits other than 3 and 8.at n=19A036317
• a(n) = 3^n*(n^3 - 3*n^2 + 2*n + 162)/162.at n=8A081914
• Number of nonisomorphic groups with orders indexed by least prime signatures.at n=27A098887
• Let b(0)=1/2, b(n) = (b(n-1)+Prime[n])/2; sequence gives 2^(n+1)*b(n).at n=9A112044
• Starting numbers for which the RATS sequence has eventual period 3.at n=0A114613
• a(n) = Sum_{d|n} d*binomial(n/d+d-2,d-1).at n=47A157020
• Initial value x of a RATS trajectory x->A036839(x) ending in a cycle unreachable by any smaller initial value.at n=9A161590
• Numbers k such that 12321*2^k + 1 is prime.at n=29A180924
• RATS: Reverse Add Then Sort the digits applied to previous term, starting with 20169.at n=0A209878
• spt(n) - p(n): total number of smallest parts in all partitions of n minus the number of partitions of n.at n=29A215513
• Index sequence for limit-block extending A000002 (Kolakoski sequence) with first term as initial block.at n=39A246145
• Ulam numbers k such that k/3 is also an Ulam number.at n=31A287212
• Number of pairs (lambda,mu) of partitions lambda of n and mu of seven with mu <= lambda (by diagram containment).at n=17A303857
• Number of tilings of a 16 X n rectangle using 2*n copies of the disconnected shape [oooo____oooo].at n=31A323483
• Mark the points of the Farey series F_n on a strip of paper and wrap it around a circle of circumference 1 so the endpoints 0 and 1 coincide; draw a chord between every pair of the Farey points; a(n) is the number of vertices in the resulting graph.at n=8A359116
• Terms of A046337 for which A358777 is zero, where the latter is the Dirichlet inverse of former's characteristic function.at n=31A359607
• G.f. satisfies A(x) = 1 + x*A(x)*(2 + A(x)^3).at n=5A364432