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 A363281 Numbers which are the sum of 4 squares of distinct primes. 1
 87, 159, 183, 199, 204, 207, 231, 247, 252, 303, 319, 324, 327, 343, 348, 351, 364, 367, 372, 399, 423, 439, 444, 463, 468, 471, 484, 487, 492, 495, 511, 516, 532, 535, 540, 543, 556, 559, 564, 567, 583, 588, 591, 604, 607, 612, 628, 655, 660, 663, 676, 679, 684, 700, 703, 708 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS David A. Corneth, Table of n, a(n) for n = 1..10000 EXAMPLE 87 is a term as 87 = 2^2 + 3^2 + 5^2 + 7^2. MATHEMATICA Select[Range@1000, Length[PowersRepresentations[#, 4, 2] // Select[AllTrue@PrimeQ] // Select[DuplicateFreeQ]] > 0 &] PROG (Python） from itertools import combinations as comb ps=[p**2 for p in [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31]] a=[n for n in range(1001) if n in [sum(n) for n in list(comb(ps, 4))]] print(a) (PARI) upto(n) = {if(n <= 86, return([])); my(pr = primes(primepi(sqrtint(n - 38))), res = List()); forvec(v = vector(4, i, [1, #pr]), c = sum(i = 1, #v, pr[v[i]]^2); if(c <= n, listput(res, c)), 2); listsort(res, 1); res} \\ David A. Corneth, Jul 12 2023 CROSSREFS Cf. A133524, A051395. Sequence in context: A095567 A205672 A039489 * A031891 A147140 A044257 Adjacent sequences: A363278 A363279 A363280 * A363282 A363283 A363284 KEYWORD easy,nonn AUTHOR Zhining Yang, May 25 2023 STATUS approved

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Last modified August 14 10:24 EDT 2024. Contains 375159 sequences. (Running on oeis4.)