A261620 Numbers n such that 10^(n-1) - pi(n) is prime.

31, 536, 2684, 7795, 8482, 49009, 96339, 236060

Offset

1,1

Comments

a(9) > 260843.

Links

Table of n, a(n) for n=1..8.

Mathematica

Select[Range[50000], PrimeQ[10^(# - 1) - PrimePi[#]] &]

Prog

(PARI) is(n) = ispseudoprime(10^(n-1) - primepi(n)) \\ Michel Marcus, Sep 10 2015

Crossrefs

Cf. A110068.

Sequence in context: A278558 A022659 A038395 * A196492 A240420 A022755

Adjacent sequences: A261617 A261618 A261619 * A261621 A261622 A261623

Keyword

more,nonn

Author

Robert Price, Sep 09 2015

Status

approved