A248352 Numbers k such that 10^k - 987654321 is prime.

986, 1240, 1928, 4054, 14252, 47528, 101728

Offset

1,1

Comments

Note that 987654321 is the largest pandigital number in base-10, omitting 0.

Links

Table of n, a(n) for n=1..7.

Mathematica

Select[Range[10000], PrimeQ[10^# - 987654321] &] (* Robert Price, Dec 05 2019 *)

Prog

(PARI) for(n=1, 10^4, if(ispseudoprime(10^n-987654321), print1(n, ", ")))

Crossrefs

Cf. A248349, A248350, A248351, A050289.

Sequence in context: A183718 A163025 A069299 * A072316 A222351 A221696

Adjacent sequences: A248349 A248350 A248351 * A248353 A248354 A248355

Keyword

nonn,hard,more

Author

Derek Orr, Oct 05 2014

Extensions

a(6)-a(7) from Robert Price, Dec 05 2019

Status

approved