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 A280409 #34 Jun 07 2025 13:07:03
%S A280409 2,3,5,7,11,17,13,23,53,19,29,41,31,47,71,107,137,103,233,263,593,167,
%T A280409 251,283,479,719,1619,911,1367,577,433,61,37,59,89,67,101,43,83,73,
%U A280409 113,79,179,269,131,197,97,149,109,173,139,157,127,191,431,647,971
%N A280409 Primes in the order that they appear in A280408, without repetitions.
%H A280409 David Radcliffe, <a href="/A280409/b280409.txt">Table of n, a(n) for n = 1..10000</a>
%t A280409 DeleteDuplicates@ Flatten@ Table[Select[NestWhileList[If[EvenQ@ #, #/2, 3 # + 1] &, n, # > 1 &], PrimeQ], {n, 200}] (* _Michael De Vlieger_, Jan 02 2017 *)
%Y A280409 Cf. A280408, A000040, A070165.
%K A280409 nonn
%O A280409 1,1
%A A280409 _Matthew Campbell_, Jan 02 2017