A204578 - OEIS

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A204578

Primes of the form 5^k-2.

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

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OFFSET

1,1

COMMENTS

See the sequence A109080 for the corresponding exponents k.

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

LINKS

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

FORMULA

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

PROG

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