OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A070258(n) + 1. - Amiram Eldar, Feb 09 2021
EXAMPLE
243 is in the sequence because 242 = 2 * 11^2, 243 = 3^5, 244 = 2^2 * 61.
244 is also in the sequence because 245 = 5 * 7^2.
But 245 is not in the sequence because 246 = 2 * 3 * 41.
MATHEMATICA
Select[Range@3051, And @@ Not /@ SquareFreeQ /@ {#-1, #, #+1} &] (* Giovanni Resta, Jan 12 2014 *)
Select[Range[2000], Union[MoebiusMu[{# - 1, #, # + 1}]] == {0} &] (* Alonso del Arte, Jan 12 2014 *)
PROG
(PARI) isok(n) = !issquarefree(n) && !issquarefree(n-1) && !issquarefree(n+1); \\ Michel Marcus, Jan 12 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jan 12 2014
EXTENSIONS
Terms corrected by Michel Marcus, Jan 12 2014
STATUS
approved