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A121619
Indices n such that Nexus numbers of order 7 (A022523(n-1) = n^7 - (n-1)^7) are primes.
9
2, 4, 7, 8, 9, 10, 12, 17, 26, 33, 36, 39, 41, 49, 51, 55, 59, 66, 78, 79, 80, 88, 96, 98, 104, 113, 118, 120, 123, 135, 136, 142, 146, 156, 157, 160, 162, 173, 176, 194, 210, 219, 220, 221, 222, 224, 232, 234, 247, 281, 291, 297, 298, 305
OFFSET
1,1
COMMENTS
Corresponding Nexus primes of order 7 (or primes of form A022523(n-1) = n^7 - (n-1)^7) are listed in A121618[n] = {127, 14197, 543607, 1273609, 2685817, 5217031, 16344637, 141903217,...}.
LINKS
MATHEMATICA
t = {}; Do[np7 = n^7 - (n - 1)^7; If[PrimeQ[np7], AppendTo[t, n]], {n, 305}]; t (* Carl R. White, Feb 28 2008 *)
Flatten[Position[Partition[Range[400]^7, 2, 1], _?(PrimeQ[#[[2]]- #[[1]]]&), {1}, Heads->False]]+1 (* or *) Select[Range[400], PrimeQ[#^7-(#-1)^7]&] (* Harvey P. Dale, Mar 19 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Alexander Adamchuk, Aug 10 2006
EXTENSIONS
More terms from Carl R. White, Feb 28 2008
STATUS
approved