cp's OEIS Frontend

A180600 a(n+1) = a(n) if A180458(n+1) = A180458(n), otherwise a(n+1) = a(n)+1.

%I A180600 #16 Dec 18 2020 16:24:12
%S A180600 1,2,3,4,5,5,5,5,6,6,6,7,7,7,8,8,9,9,10,10,10,11,11,12,12,13,13,13,13,
%T A180600 14,15,16,16,16,17,18,18,19,19,20,20,21,22,22,22,22,23,24,24,24,25,25,
%U A180600 25,26,27,28,28,28,29,29,30,31,32,32,33,33,34,35,36,36,37,37,38,39,39,40,40,41
%N A180600 a(n+1) = a(n) if A180458(n+1) = A180458(n), otherwise a(n+1) = a(n)+1.
%C A180600 This arithmetic sequence grows with slope 1 where A180458 increases, and has terraces (zero slope) where A180458 has terraces.
%H A180600 Harvey P. Dale, <a href="/A180600/b180600.txt">Table of n, a(n) for n = 1..1000</a>
%F A180600 a(n+1) = a(n) + min(1, A180458(n+1)-A180458(n)). - _R. J. Mathar_, Oct 24 2010
%p A180600 isA002113 := proc(n) n = digrev(n) ; end proc:
%p A180600 A180458 := proc(n) local p ; p := ithprime(n) ; while not isA002113(p) do p := p-1 ; end do; p ; end proc:
%p A180600 A180600 := proc(n) option remember; if n = 1 then 1; else if A180458(n) = A180458(n-1) then procname(n-1) ; else procname(n-1)+1 ; end if; end if; end proc:
%p A180600 seq(A180600(n),n=1..90) ; # _R. J. Mathar_, Oct 24 2010
%t A180600 lpn[n_]:=Module[{k=0},While[!PalindromeQ[n-k],k++];n-k]; nxt[{n_,l_,a_}] := Module[{x=lpn[Prime[n+1]]},{n+1,x,If[x==l,a,a+1]}]; NestList[ nxt,{1,1,1},80][[All,3]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 18 2020 *)
%K A180600 easy,nonn,base
%O A180600 1,2
%A A180600 _Giovanni Teofilatto_, Sep 11 2010
%E A180600 Sequence corrected starting near a(54), definition corrected, comment and formula added by _R. J. Mathar_, Oct 24 2010