31809

Appears in sequences

• Indices of primes in sequence defined by A(0) = 19, A(n) = 10*A(n-1) - 81 for n > 0.at n=17A102008
• Monotonic ordering of set S generated by these rules: if x and y are in S then 2xy-x-y is in S, and 3 is in S.at n=18A192525
• 8-step Fibonacci sequence starting with 0,0,0,0,0,1,0,0.at n=23A251740
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 211", based on the 5-celled von Neumann neighborhood.at n=36A270899
• Numbers k such that k![4] - 2 is prime, where k![4] = A007662(k) = quadruple factorial.at n=40A283554
• a(n) is the first number that is the start of a string of exactly n consecutive numbers in A358350.at n=15A359248