A283158 Numbers k such that A011544(k-1) is a prime.

1, 85, 555, 1508, 1781, 4224, 7037, 43740

Offset: 1

Author

XU Pingya, Mar 01 2017

Keywords

• nonn
• base
• more
• hard

Comments

For k <= 16000, there are seven primes in sequence A011544.

Round(e*10^112279) = floor(e*10^112279), and floor(e*10^112279) = A011544(112279) (=A007512(7)) is a prime. Thus 112280 = A064118(7) is also a term.

Links

• Eric Weisstein's World of Mathematics, e-Prime

Crossrefs

Cf. A007512, A011543, A011544, A064118.

Programs

Mathematica

Do[If[PrimeQ[Round[E*10^(n-1)]],Print[n]],{n,16000}]

Extensions

a(2) = 85 added by Jason Yuen, Jun 16 2025

a(8) from Michael S. Branicky, Jun 24 2025