This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A331435 #29 Jan 20 2020 12:52:34 %S A331435 1,2,1,6,5,4,10,11,10,14,15,1,14,5,9,20,21,24,19,4,6,26,26,12,14,29, %T A331435 16,31,29,22,24,31,34,1,26,5,28,35,40,19,41,39,44,38,29,45,42,4,6,35, %U A331435 51,16,46,20,51,54,55,56,56,30,52,54,34,36,56,58,40,9,11 %N A331435 a(n) is the least positive k such that A028916(n) - k^2 is a fourth power. %H A331435 Rémy Sigrist, <a href="/A331435/b331435.txt">Table of n, a(n) for n = 1..10000</a> %H A331435 Rémy Sigrist, <a href="/A331435/a331435.gp.txt">PARI program for A331435</a> %H A331435 Wikipedia, <a href="http://en.wikipedia.org/wiki/Friedlander%E2%80%93Iwaniec_theorem">Friedlander-Iwaniec theorem</a> %e A331435 The first terms, alongside A028916(n), are: %e A331435 n a(n) A028916(n) %e A331435 -- ---- ---------------- %e A331435 1 1 2 = 1^2 + 1^4 %e A331435 2 2 5 = 2^2 + 1^4 %e A331435 3 1 17 = 1^2 + 2^4 %e A331435 4 6 37 = 6^2 + 1^4 %e A331435 5 5 41 = 5^2 + 2^4 %e A331435 6 4 97 = 4^2 + 3^4 %e A331435 7 10 101 = 10^2 + 1^4 %e A331435 8 11 137 = 11^2 + 2^4 %e A331435 9 10 181 = 10^2 + 3^4 %e A331435 10 14 197 = 14^2 + 1^4 %o A331435 (PARI) See Links section. %Y A331435 See A002331, A331521, A331522, A331523, A331524, A331525, A331526 and A331527 for similar sequences. %Y A331435 Cf. A000583, A028916. %K A331435 nonn %O A331435 1,2 %A A331435 _Rémy Sigrist_, Jan 18 2020