A204578 Primes of the form 5^k-2.

3, 23, 6103515623, 1490116119384765623, 88817841970012523233890533447265623, 11754943508222875079687365372222456778186655567720875215087517062784172594547271728515623, 44841550858394146269559346665277316200968382140048504696226185084473314645947539247572422027587890623

Offset: 1

Author

M. F. Hasler, Jan 30 2012

Keywords

• nonn
• less

Comments

See the sequence A109080 for the corresponding exponents k.

The number a(3) = 6103515623 is also in A095304, A104090 and A128472.

Crossrefs

Cf. A109080.

Programs

PARI

for(i=0,999, ispseudoprime(t=5^i-2) & print1(t","))

Formula

a(n) = 5^A109080(n)-2.