A214515 Numbers of the form p^2 + q^2 + r^2 + s^2, where p, q, r, and s are primes.
16, 21, 26, 31, 36, 37, 42, 47, 52, 58, 61, 63, 66, 68, 71, 76, 79, 82, 84, 87, 92, 100, 103, 106, 108, 111, 116, 124, 127, 132, 133, 138, 143, 148, 151, 154, 156, 159, 164, 172, 175, 178, 180, 181, 183, 186, 188, 191, 196, 199, 202, 204, 207, 212, 220, 223
Offset: 1
Keywords
Links
- T. D. Noe, Table of n, a(n) for n = 1..10000
Programs
-
Mathematica
nn = 10^3; ps = Prime[Range[PrimePi[Sqrt[nn]]]]; t = Flatten[Table[ps[[i]]^2 + ps[[j]]^2 + ps[[k]]^2 + ps[[l]]^2, {i, Length[ps]}, {j, i, Length[ps]}, {k, j, Length[ps]}, {l, k, Length[ps]}]]; t = Select[t, # <= nn &]; Union[t]