A127047 Primes p such that denominator of Sum_{k=1..p-1} 1/k^4 is a fourth power.
2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 53, 67, 71, 73, 97, 101, 103, 107, 109, 127, 131, 197, 199, 211, 223, 227, 229, 233, 293, 367, 373, 379, 383, 389, 397, 401, 439, 443, 449, 457, 461, 463, 557, 563, 569, 571, 577, 877, 881, 883, 967, 971, 977, 983, 991, 997
Offset: 1
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..665 from Robert Israel)
Programs
-
Maple
S:= 0: R:= NULL: count:= 0: for k from 1 while count < 100 do S:= S + 1/k^4; if isprime(k+1) and surd(denom(S),4)::integer then R:= R,k+1; count:= count+1 fi od: R; # Robert Israel, Oct 25 2019
-
Mathematica
d[n_] := Module[{}, su = 0; a = {}; For[i = 1, i <= n, i++, su = su + 1/ i^4; If[PrimeQ[i + 1], If[IntegerQ[(Denominator[su])^(1/4)], AppendTo[a, i + 1]]]]; a]; d[10000] Select[Flatten[Position[Denominator[Accumulate[1/Range[1000]^4]],?(IntegerQ[ Surd[ #,4]]&)]],PrimeQ] (* _Harvey P. Dale, Feb 08 2015 *)
Comments