A282783 Number of terms in A282430 less than or equal to 10^n.

0, 1, 1, 6, 77, 1069, 13041, 153389, 1691609, 18175623, 192338138

Offset: 0

Author

Arkadiusz Wesolowski, Feb 21 2017

Keywords

• nonn
• more

Comments

An approximate value of a(n) is given by C*10^n*(exp(-2) - 1/log(10^n)), where C = 0.209.

Crossrefs

Cf. A282430.

Programs

PARI

a(n)={t=0; forstep(m=2, 10^n, 2, if(!(m%3)==0, x=0; until(p<2||isprime(p), p=m-3^x; x++); if(p<2, t++))); return(t)};