login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A216148 Primes of the form 2*n^n+1 = A216147(n). 13
3, 17832200896513, 78692816150593075150849 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence should be extended through A110932, which lists the n-values: The next term, 2*251^251+1 = A216147(A110932(4)) ~ 4.16*10^602, is too large to be displayed within 3 lines.

LINKS

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

C. Caldwell, G.L. Honaker (Eds), Prime Curios!: 78692816150593075150849.

"Jim", Topic: The Lost Proof of Fermat, on mathforum.org, Jan 31 2004

FORMULA

a(2) = A216147(12) = A005109(95) = A070855(12) = A058383(89) = A133663(18).

a(3) = A216147(18) = A005109(183)= A070855(18) = A058383(177)= A133663(36).

MATHEMATICA

Select[Table[2n^n+1, {n, 20}], PrimeQ] (* Harvey P. Dale, Mar 27 2016 *)

PROG

(PARI) for(n=1, 999, ispseudoprime(p=n^n*2+1) & print1(p", "))

CROSSREFS

Cf. A110932.

A subsequence of A133663, with b=a and c=1.

Sequence in context: A275939 A230810 A266199 * A058453 A058471 A068740

Adjacent sequences:  A216145 A216146 A216147 * A216149 A216150 A216151

KEYWORD

nonn,bref,less

AUTHOR

M. F. Hasler, Sep 02 2012

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 16 10:52 EDT 2019. Contains 327095 sequences. (Running on oeis4.)