Pairs of positive numbers x <= y such that x^4 + y^4 is prime and increasing.
1, 1, 1, 2, 2, 3, 1, 4, 3, 4, 2, 5, 4, 5, 1, 6, 2, 7, 4, 7, 6, 7, 3, 8, 5, 8, 2, 9, 8, 9, 7, 10, 2, 11, 4, 11, 6, 11, 9, 10, 4, 13, 10, 13, 5, 14, 12, 13, 8, 15, 1, 16, 3, 16, 5, 16, 13, 14, 11, 16, 2, 17, 4, 17, 14, 15, 5, 18, 7, 18, 11, 18, 14, 17, 2, 19, 6, 19
1
That is, the (x,y) pairs are sorted by the value x^4 + y^4. This sequence differs from S000586 starting at pair 17.
T. D. Noe, Plot of 2500 pairs
T. D. Noe, Table of 2500 pairs
Cf. A002644, S000586, S000591-S000596.
nonn
T. D. Noe, Apr 22 2015