22205

Appears in sequences

• n*10^3-1, n*10^3-3, n*10^3-7 and n*10^3-9 are all prime.at n=13A064977
• Fourth row of Pascal-(1,3,1) array A081578.at n=13A081586
• Indices of primes in sequence defined by A(0) = 27, A(n) = 10*A(n-1) - 13 for n > 0.at n=14A101962
• Number of permutations of length n which avoid the patterns 213, 1234, 2431.at n=14A116726
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 1, -1), (1, 0, 0), (1, 0, 1), (1, 1, 1)}.at n=7A151176
• Beach-Williams Pell numbers of type k^2 + 4.at n=5A212083
• Numbers n where tau(n) and n-tau(n) are perfect squares, with tau(n) the number of divisors of n (A000005).at n=38A245197
• Numbers k = concat(s,t) such that k = (Fibonacci(s) mod k) * (Fibonacci(t) mod k).at n=4A272770
• a(n) = prime(1)^2 + prime(n)^2.at n=34A287922
• Expansion of e.g.f. tan(x*tan(x/2)) (even powers only).at n=5A296839
• a(n) = (4*n^3 - 6*n^2 + 14*n + 3)/3.at n=26A321124
• Numerator of the limiting density of residues attained by the Fibonacci sequence modulo powers of the n-th prime.at n=41A350999
• Semiprimes of the form k^2 + 4.at n=32A360741