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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A121616 Primes of form (n+1)^5 - n^5 = A022521(n). 11
31, 211, 4651, 61051, 371281, 723901, 1803001, 2861461, 4329151, 4925281, 7086451, 7944301, 14835031, 19611901, 23382031, 44119351, 54664711, 86548801, 97792531, 162478501, 189882031, 267217051, 293109961, 306740281, 490099501 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Might be called "Pentan primes" (in analogy with Cuban primes, of the form (n+1)^3-n^3), or "Nexus primes of order 5" (cf. link below).

Indices n such that Nexus number of order 5 (or A022521(n-1) = n^5 - (n-1)^5) is prime are listed in A121617 = {2, 3, 6, 11, 17, 20, 25, 28, 31, 32, 35, 36, 42, 45, 47, 55, 58, 65, 67, 76, 79, 86, 88, 89, 100,...}.

The last digit is always 1 because 5 is the Pythagorean prime A002144(1). a(1) = 31 is the Mersenne prime A000668(3).

LINKS

Zak Seidov, Table of n, a(n) for n = 1..2000.

MATHEMATICA

Select[Table[n^5 - (n-1)^5, {n, 1, 200}], PrimeQ]

CROSSREFS

Cf. A022521, A000040, A000043, A002144, A000668, A002407, A121617, A121618, A121619, A121620.

Sequence in context: A152730 A090027 A164784 * A062393 A183792 A183784

Adjacent sequences:  A121613 A121614 A121615 * A121617 A121618 A121619

KEYWORD

nonn

AUTHOR

Alexander Adamchuk, Aug 10 2006

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 7 17:07 EST 2016. Contains 278888 sequences.