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A254380 2^2*3^3*...*a(n)^a(n) + 1 is prime, a(n) is prime, a(n)>a(n-1), and a(n) is minimal. 0
2, 3, 19, 11251 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Observation: a(2)..a(4) coincide with a(1)..a(3) from A191623. - Omar E. Pol, Jan 30 2015

LINKS

Table of n, a(n) for n=1..4.

Chris K. Caldwell and G. L. Honaker, Jr. Prime Curios!

EXAMPLE

a(1)=2 because 2 and (2^2)+1=5 are prime.

a(2)=3 because 3 and (2^2*3^3)+1=109 are prime.

a(3)=19 because 19 and (2^2*3^3*19^19)+1=213669322811313867625389733 are prime, and this did not work for either 5, 7, 11, 13.

CROSSREFS

Cf. A000040, A051674, A191623.

Sequence in context: A014547 A066735 A232498 * A099069 A038584 A108022

Adjacent sequences:  A254377 A254378 A254379 * A254381 A254382 A254383

KEYWORD

nonn,hard,more

AUTHOR

G. L. Honaker, Jr., Jan 29 2015

EXTENSIONS

a(4) found by Chris K. Caldwell

STATUS

approved

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Last modified February 23 21:20 EST 2020. Contains 332195 sequences. (Running on oeis4.)