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 A309123 #12 Jul 14 2019 18:01:30 %S A309123 50,71,267,517,2274,1508,3884,1971,444,667,817,286,535,732,856,2926, %T A309123 541,736,858,293,542,233,483,695,834,2888,16995,41225,20304,4506,6713, %U A309123 2591,5091,22564,47502,21795,46686,21607,46484,215602,46433,68142,261041,510922 %N A309123 a(1) = 50 and for any n > 0, a(n+1)^2 is the smallest square that begins with a(n). %C A309123 This sequence is similar to A308055. %C A309123 The initial value (50) seems to be the first one for which the iteration of A018796 diverges; there are neither duplicates nor squares among the first 79000 terms. %H A309123 Rémy Sigrist, <a href="/A309123/b309123.txt">Table of n, a(n) for n = 1..1000</a> %H A309123 Rémy Sigrist, <a href="/A309123/a309123.gp.txt">PARI program for A309123</a> %F A309123 a(1) = 50 and then a(n+1) = A018796(a(n)) for n > 0. %e A309123 The first terms, alongside the square of a(n+1), are: %e A309123 n a(n) a(n+1)^2 %e A309123 -- ---- -------- %e A309123 1 50 5041 %e A309123 2 71 71289 %e A309123 3 267 267289 %e A309123 4 517 5171076 %e A309123 5 2274 2274064 %e A309123 6 1508 15085456 %e A309123 7 3884 3884841 %e A309123 8 1971 197136 %e A309123 9 444 444889 %e A309123 10 667 667489 %e A309123 11 817 81796 %e A309123 12 286 286225 %e A309123 13 535 535824 %e A309123 14 732 732736 %e A309123 15 856 8561476 %e A309123 16 2926 292681 %o A309123 (PARI) See Links section. %Y A309123 Cf. A018796, A308055. %K A309123 nonn,base %O A309123 1,1 %A A309123 _Rémy Sigrist_, Jul 13 2019