851927
domain: N
Appears in sequences
- Composite numbers n such that the sum of divisors of n, sigma(n), divided by the number of divisors, d(n) and sigma(n) minus n are both rational squares.at n=25A049226
- a(n) = 4*n^4 + 8*n^3 - 4*n - 1 = (2*n^2 - 1)*(2*n^2 + 4*n + 1).at n=21A057769
- Odd composite n such that n divides Fibonacci(n) + 1.at n=17A094395
- Composite numbers k that divide both Fibonacci(k+1) and Fibonacci(k) + 1.at n=13A094411
- Numbers n such that sum of divisors, sigma(n), and sum of the proper divisors, sigma(n)-n, are both square.at n=19A176996
- Semiprimes k that divide Fibonacci(k+1).at n=51A177745
- Frobenius pseudoprimes == 2,3 (mod 5) with respect to Fibonacci polynomial x^2 - x - 1.at n=10A212423
- Worst cases for Hart's one-line factorization (OLF) method with multiplier M = 1, see comments.at n=21A284522