OFFSET
1,1
COMMENTS
It can be proved that any number in the gap between n! + (n-1)! + (n-2)! + ... + 2! + 1! + 0! and (n+1)! - (n! + (n-1)! + (n-2)! + ... + 2! + 1! + 0!) is in this sequence.
0! and 1! are treated as distinct. - Bernard Schott, Feb 25 2019
EXAMPLE
10 can be represented as 10 = 0! + 1! + 2! + 3!, so it is not a term.
11 cannot be represented as a sum or a difference of factorials, so it is a term.
MATHEMATICA
Complement[Range[160], Total[# Range[0, 5]!] & /@ (IntegerDigits[ Range[3^6 - 1], 3, 6] - 1)] (* Giovanni Resta, Feb 27 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Ivan Stoykov, Feb 25 2019
EXTENSIONS
More terms from Giovanni Resta, Feb 27 2019
STATUS
approved