A168270 Squarefree numbers which are also isolated numbers.
2, 6, 23, 30, 37, 42, 47, 53, 67, 79, 83, 89, 97, 102, 113, 127, 131, 138, 157, 163, 167, 173, 211, 223, 233, 251, 257, 263, 277, 282, 293, 307, 317, 331, 337, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 439, 443, 449, 457, 462, 467, 479, 487, 491, 499, 503, 509
Offset: 1
Keywords
Programs
-
Maple
isA007510 := proc(n) if isprime(n) then not isprime(n-2) and not isprime(n+2) ; else false; end if ; end proc: isA014574 := proc(n) isprime(n+1) and isprime(n-1) ; end proc: isA167706 := proc(n) isA007510(n) or isA014574(n) ; end proc: isA005117 := proc(n) n =1 or numtheory[issqrfree](n) ; end proc: isA168270 := proc(n) isA005117(n) and isA167706(n) ; end proc: for n from 1 to 600 do if isA168270(n) then printf("%d,",n) ; fi; od: # R. J. Mathar, Dec 09 2009
Extensions
Corrected (missing terms inserted) by R. J. Mathar, Dec 09 2009