18807

Appears in sequences

• Perrin sequence (or Perrin numbers, or Ondrej Such sequence): a(n) = a(n-2) + a(n-3) with a(0) = 3, a(1) = 0, a(2) = 2.at n=35A001608
• Number of primes less than 10000n.at n=20A038813
• Numbers whose base-7 representation contains exactly four 5's.at n=30A043416
• Primonacci numbers: a(n)=a(n-2)+a(n-3)+a(n-5)+a(n-7)+a(n-11)+...+a(n-p(k))+... until n <= p(k), where p(k) is the k-th prime. a(1)=a(2)=1.at n=27A078465
• Least positive k such that 2^n + k is a Chen prime and 2^n + k + 2 is a brilliant number.at n=44A109364
• a(n) = floor(r^n) where r is the smallest Pisot number (real root r=1.3247179... of x^3-x-1).at n=35A112639
• Number of ways to build a contiguous building with n LEGO blocks of size 1 X 7 on top of a fixed block of the same size so that the building is flat, i.e., with all blocks in parallel position and symmetric after a rotation by 180 degrees.at n=8A123809
• Least k such that the last n decimal digits of 2^k are all powers of 2.at n=9A139126
• a(n) = round(r^n) where r is the smallest Pisot number (real root r=1.3247179.. of x^3-x-1).at n=35A205579
• Number of partitions of n into distinct parts with boundary size 7.at n=41A227564
• Numbers n not divisible by 2 such that n^2 written in base 4 has no digit > 1.at n=10A257284
• Number of palindromic compositions of n into prime parts.at n=54A276420
• Number of minimal total dominating sets in the n-cycle graph.at n=34A300738
• Fourth Lie-Betti number of a path graph on n vertices.at n=22A362007