A280297 Numbers n such that F(n) and F(n-1) are not squarefree where F(n) = A000045(n).

25, 91, 126, 175, 225, 276, 325, 426, 456, 475, 576, 625, 637, 703, 726, 775, 820, 876, 925, 979, 1001, 1002, 1026, 1075, 1176, 1183, 1225, 1275, 1326, 1375, 1431, 1476, 1525, 1548, 1625, 1626, 1675, 1729, 1776, 1825, 1926, 1975, 2076, 2094, 2125, 2148, 2226

Offset: 1

Author

Altug Alkan, Dec 31 2016

Keywords

• nonn

Comments

Utilized the factorization of Fibonacci numbers in the FactorDB.com database. - Robert Price, Feb 27 2017

Examples

			25 is a term because Fibonacci(25) = 5^2 * 3001 and Fibonacci(24) = 2^5 * 3^2 * 7 * 23.
		

Links

• Robert Price, Table of n, a(n) for n = 1..108
• FactorDB, Factorizations of F(1000) ... F(1019).

Crossrefs

Cf. A000045, A013929, A037917.

Programs

PARI

is(n) = !issquarefree(fibonacci(n)) && !issquarefree(fibonacci(n-1));

Extensions

a(8)-a(108) from Robert Price, Feb 27 2017