login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A191865
Primes of the form (n-1)^6 + n^5 + (n+1)^4.
1
17, 563, 67559, 758677727, 5639788283, 12519315713, 228317617103, 2215267259747, 2458514680949, 5331791014853, 9754511753219, 11469661520567, 60568409162663, 64329745367417, 148696534573127, 164890314104507, 1843608625927967, 2182930574787737, 5990875533026939
OFFSET
1,1
COMMENTS
Sum of three consecutive numbers using exponents 6, 5, and 4 to generate prime numbers from n^6 - 5n^5 + 16n^4 - 16n^3 + 21n^2 - 2n + 2 = (n-1)^6 + n^5 + (n+1)^4.
EXAMPLE
2^6 + 3^5 + 4^4 = 563 and 6^6 + 7^5 + 8^4 = 67559 are primes in the sequence.
MAPLE
R:= NULL: count:= 0:
for n from 1 by 2 while count < 100 do
v:= (n-1)^6+n^5+(n+1)^4;
if isprime(v) then count:= count+1; R:= R, v; fi
od:
R; # Robert Israel, Jan 05 2021
MATHEMATICA
lst={}; Do[If[PrimeQ[p=(n-1)^6+n^5+(n+1)^4], AppendTo[lst, p]], {n, 200}]; lst
lst={}; Do[If[PrimeQ[p=n^6-5n^5+16n^4-16n^3+21n^2-2n+2], AppendTo[lst, p]], {n, 200}]; lst
PROG
(PARI) forstep(n=1, 1e3, 2, if(isprime(k=(n-1)^6+n^5+(n+1)^4), print1(k", "))) \\ Charles R Greathouse IV, Jun 19 2011
CROSSREFS
Sequence in context: A197395 A280181 A012069 * A249862 A056771 A041547
KEYWORD
nonn
AUTHOR
Rafael Parra Machio, Jun 18 2011
STATUS
approved