A074382 Difference between (1+3^n)-th and (3^n)-th primes.

1, 2, 6, 4, 2, 6, 2, 12, 12, 12, 30, 18, 24, 10, 14, 32, 22, 12, 14, 10, 6, 12, 30, 44, 40, 54, 28, 8, 24, 26, 6, 8, 28, 48, 12, 158, 20

Offset

0,2

Links

Table of n, a(n) for n=0..36.

Formula

a(n) = prime(1+3^n) - prime(3^n).

Example

n=25: a(25)=54 because the 847288609443rd prime is 25270000074757 and the 847288609444th prime is 25270000074811.

Mathematica

NextPrime[#]-#&/@Table[Prime[3^n], {n, 25}] (* Harvey P. Dale, Sep 29 2015 *)

Crossrefs

Cf. A074325, A038833.

Sequence in context: A021795 A008904 A334397 * A061350 A046276 A368516

Adjacent sequences: A074379 A074380 A074381 * A074383 A074384 A074385

Keyword

hard,more,nonn

Author

Labos Elemer, Aug 22 2002

Extensions

Corrected by Harvey P. Dale, Sep 29 2015

a(0), a(26)-a(36) from Chai Wah Wu, Aug 30 2019

Status

approved