OFFSET
0,11
FORMULA
EXAMPLE
a(10344) = 4 because 4 of the digits of 10344 (1, 0, 4 and 4) are nonprime.
MATHEMATICA
a[n_] := Length@ Intersection[ IntegerDigits[n], {0, 1, 4, 6, 8, 9}]; a/@ Range[0, 90] (* Giovanni Resta, Jul 14 2015 *)
Table[Count[IntegerDigits[n], _?(!PrimeQ[#]&)], {n, 0, 100}] (* Harvey P. Dale, Jan 16 2017 *)
CROSSREFS
KEYWORD
dead
AUTHOR
Giovanni Teofilatto, Jul 12 2015
EXTENSIONS
Corrected and extended by Giovanni Resta, Jul 14 2015
Corrected and extended by Harvey P. Dale, Jan 16 2017
STATUS
approved