A231593 Total number of 4's digits in primes less than 10^n.

0, 3, 34, 360, 3772, 39006, 397474, 4022501, 40604951, 408986159, 4113511677, 41331763006, 414971464358, 4163826451096

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

a(2)=3, since there are 3 4's in primes less than 100. Namely: 41, 43, 47.

Mathematica

Table[Count[IntegerDigits[Prime[Range[PrimePi[10^n - 1]]]], 4, 2], {n, 7}] (* Robert Price, Jun 16 2019 *)

Crossrefs

Cf. A231411, A231590-A231598, A119290, A119291-A119300.

Sequence in context: A066265 A268802 A284891 * A367509 A134491 A045727

Adjacent sequences: A231590 A231591 A231592 * A231594 A231595 A231596

Keyword

nonn,base,more

Author

Robert Price, Nov 11 2013

Extensions

a(14) from Giovanni Resta, Jul 20 2015

Status

approved