A316868 Number of times 7 appears in decimal expansion of n.

0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0

Offset

0,78

Links

Table of n, a(n) for n=0..104.

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

Cf. A043517, A043518, A043519, A043520.

Cf. A055641, A268643, A316863, A316864, A316865, A316866, A316867, A316869, A102683.

Cf. A079692.

Sequence in context: A086073 A053622 A016408 * A106822 A203905 A309142

Adjacent sequences: A316865 A316866 A316867 * A316869 A316870 A316871

Keyword

base,easy,nonn

Author

Robert G. Wilson v, Jul 15 2018

Status

approved