OFFSET
0,78
EXAMPLE
a(0) = 0 since the decimal representation of 0 does not contain the digit 7.
a(7) = 1 since 7 appears once in the decimal expansion of 7.
MATHEMATICA
Array[ DigitCount[#, 10, 7] &, 105, 0]
PROG
(PARI) a(n) = #select(x->x==7, digits(n)); \\ Michel Marcus, Jul 20 2018
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Robert G. Wilson v, Jul 15 2018
STATUS
approved