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 A355506 #28 May 09 2025 02:58:57
%S A355506 1,2,4,6,8,3,10,12,5,14,16,7,18,20,22,9,24,26,11,28,30,32,13,34,36,15,
%T A355506 38,40,42,17,44,46,19,48,50,21,52,54,56,23,58,60,25,62,64,66,27,68,70,
%U A355506 29,72,74,31,76,78,80,33,82,84,35,86,88,90,37,92,94,39,96,98,41,100,102,104,43,106
%N A355506 a(n) is the least positive integer not occurring earlier in the sequence such that, if a(m) = a(n)+1, then |m - n| >= a(n).
%C A355506 A permutation of the positive integers (or of the nonnegative integers, if prefixed by a(0) = 0). It seems that all the odd numbers occur in order at indices A184119 and the even numbers occur in order at indices A136119, except for the initial 1 and 2. - _M. F. Hasler_, Jul 04 2022
%C A355506 The graph of the sequence has two "rays", one with slope 0.583 that contains only every third or fourth value, and one with slope 1.42 which contains the other values. - _M. F. Hasler_, May 09 2025
%H A355506 <a href="/index/Per#IntegerPermutation">OEIS Index to sequences related to permutations of the positive (or nonnegative) integers</a>.
%e A355506 The distance between a(3) = 4 and a(9) = 5 is |3 - 9| = 6, which is >= 4.
%o A355506 (PARI) {A355506_first(N, U=1/*starting value*/, A=Map())=vector(N, n, my(k=U); while(mapisdefined(A,k) || iferr(n < mapget(A,k-1)+k-1 || n<mapget(A,k+1)+k,E,), k++); mapput(A,k,n); k==U && until(!mapisdefined(A,U), U>2 && mapdelete(A,U-2); U++); k)} \\ _M. F. Hasler_, Jul 05 2022
%Y A355506 Cf. A184119, A136119.
%Y A355506 Cf. A353592 (inverse permutation).
%K A355506 nonn
%O A355506 1,2
%A A355506 _Ali Sada_, Jul 04 2022
%E A355506 More terms from _M. F. Hasler_, Jul 04 2022