OFFSET
1,1
COMMENTS
Each of a(n), a(n)-1, a(n)-2, a(n)+1, a(n)+2 has at least one square divisor.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A078144(n) + 2. - Amiram Eldar, Feb 09 2021
EXAMPLE
846 = 2*3^2*47, 846 - 1 = 5*13^2, 846 - 2 = 2^2*211, 846 + 1 = 7*11^2, 846 + 2 = 2^4*53.
MATHEMATICA
Select[Range[1, 100000], !SquareFreeQ[#] &&!SquareFreeQ[#-1] &&!SquareFreeQ[#+1] &&!SquareFreeQ[#-2] &&!SquareFreeQ[#+2]&]
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladimir Joseph Stephan Orlovsky, Mar 29 2011
STATUS
approved