A335001 Integers m such that d(F(m)) = d(L(m)) where d is the number of divisors function, F(n) and L(n) are respectively the n-th Fibonacci and n-th Lucas numbers.
1, 4, 5, 7, 10, 11, 13, 14, 17, 18, 26, 46, 47, 58, 73, 77, 85, 89, 103, 107, 121, 139, 167, 179, 181, 187, 205, 221, 233, 241, 247, 253, 257, 262, 269, 273, 281, 293, 295, 317, 329, 335, 337, 341, 371, 377, 397, 407, 409, 427, 442, 454, 466, 491, 506, 563, 611
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..87
- Prapanpong Pongsriiam, Fibonacci and Lucas Numbers which have Exactly Three Prime Factors and Some Unique Properties of F18 and L18, Fibonacci Quart. 57 (2019), no. 5, 130-144.
Programs
-
PARI
lucas(n) = fibonacci(n+1)+fibonacci(n-1); isok(m) = numdiv(fibonacci(m))==numdiv(lucas(m));
Comments