27071

Appears in sequences

• For n>0, a(n) is the least quasi-Carmichael number to base -n, extended to n=0 with the least composite squarefree integer.at n=19A029591
• Composite n coprime to 5 such that Fibonacci(n) == Legendre(n,5) (mod n).at n=10A049062
• Composite k such that Fibonacci(k) == Legendre(k,5) == 1 (mod k).at n=6A093372
• Odd composites m that divide Fibonacci(m)-1.at n=12A094394
• Odd n dividing Fibonacci(n)-1 but neither Fibonacci(n-1) nor Fibonacci(n+1).at n=1A094400
• Odd numbers k that divide Fibonacci(k) - 1 but not Fibonacci(k-1).at n=7A094409
• Numerator of Euler(n, 4/31).at n=3A157607
• Number of n X 3 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.at n=13A229440
• Least integer k > 1 such that pi(k)^2 + pi(k*n)^2 is a square, where pi(.) is the prime-counting function given by A000720.at n=35A255677
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 533", based on the 5-celled von Neumann neighborhood.at n=29A272784
• Numbers k such that Fibonacci(k) == +-1 (mod k) and k is neither 1 nor prime nor twice a prime.at n=33A279072
• Sum of the odd parts in the partitions of n into 8 parts.at n=35A309629
• a(n) is the number of squares of side length greater than 1 having vertices at the points of an n X n grid of dots.at n=23A328152
• Odd composite integers m such that F(m)^2 == 1 (mod m), where F(m) is the m-th Fibonacci number.at n=34A337231