22805

Appears in sequences

• a(n) = T(2n,n+3), T given by A026725.at n=6A026843
• Position where n (presumably) appears the last time in A107261, or 0 if n keeps appearing.at n=18A107262
• Members of 3-cycles of permutation A111273.at n=20A113701
• Numbers k such that k and k^2 use only the digits 0, 2, 5, 6 and 8.at n=24A136913
• Partial sums of Sum_{k=1..n} n/gcd(n,k), or partial sums of Sum_{d|n} d*phi(d) (see A057660).at n=44A174405
• Beach-Williams Pell numbers of type k^2 + 4.at n=6A212083
• Numbers n where tau(n) and n-tau(n) are perfect squares, with tau(n) the number of divisors of n (A000005).at n=39A245197
• Numbers n such that 36n+11, 36(n+1)+11, 36(n+2)+11 and 36(n+3)+11 are prime.at n=23A255608
• Number of active (ON, black) cells at stage 2^n-1 of the two-dimensional cellular automaton defined by "Rule 502", based on the 5-celled von Neumann neighborhood.at n=7A272578
• a(n) = prime(1)^2 + prime(n)^2.at n=35A287922
• Numbers having in binary representation more zeros than their squares.at n=5A293655
• Semiprimes of the form k^2 + 4.at n=33A360741
• Number of set partitions of {1..n} such that the median of medians of the blocks is (n+1)/2.at n=9A361863
• Semiprimes k such that k+2 and k+6 are primes and k+4 and k+8 are all semiprimes.at n=12A392186