Numbers k such that k^4 is sum of two positive 7th powers.

Terms

a(0) =4a(1) =512a(2) =8748a(3) =16641a(4) =65536a(5) =312500a(6) =1119744a(7) =2130048a(8) =3294172a(9) =4787344a(10) =5359225a(11) =8388608a(12) =19131876a(13) =36393867a(14) =40000000a(15) =77948684a(16) =143327232a(17) =250994068a(18) =268468225a(19) =272646144a(20) =344882041a(21) =421654016a(22) =612780032a(23) =683437500a(24) =685980800a(25) =1073741824a(26) =1300078125