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 A118532 #14 May 26 2014 23:48:48 %S A118532 1,16,76,82,43,49,109,916,634,451,169,976,694,511,130,46,79,112,226, %T A118532 637,751,172,286,697,811,133,346,658,871,193,406,619,931,154,466,679, %U A118532 991,214,427,739,952,274,487,799,1012,2116,6127,7231,1342,2446 %N A118532 Start with 1 and repeatedly reverse the digits and add 15 to get the next term. %C A118532 This sequence never cycles. %C A118532 The plot (see the Noe link) shows 2774 terms of this sequence. It has a regular structure, which continues at higher decades. - _T. D. Noe_, May 10 2006 %H A118532 T. D. Noe, <a href="/A118532/b118532.txt">Table of n, a(n) for n = 1..2774</a> %H A118532 T. D. Noe, <a href="/A118532/a118532.gif">Plot of A118532</a> %H A118532 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %F A118532 This sequence never cycles. After a while, the pattern of length changes settles into an increasing pattern: 10^(4m)+3, 10^(4m+1)+3, 10^(4m+2)+12, 10^(4m+3)+12, 10^(4(m+1))+3, ... The key is that every two steps adds 15 at each end, unless there is a carry across the middle or a trailing 0. This allows many steps to be carried out in a single operation. - _Martin Fuller_, May 12 2006 %F A118532 a(n+1) = A004086(a(n)) + 15. - _Reinhard Zumkeller_, Jan 29 2014 %o A118532 (PARI) A118532(Nmax,Q=15,S=1)=vector(Nmax,i,if(i>1,S=A004086(S)+Q,S)) \\ - _M. F. Hasler_, May 06 2012 %o A118532 (Haskell) %o A118532 a118532 n = a118532_list !! (n-1) %o A118532 a118532_list = iterate ((+ 15) . a004086) 1 %o A118532 -- _Reinhard Zumkeller_, Jan 29 2014 %Y A118532 Cf. A117828, A117816, A117817. %K A118532 nonn,base,look %O A118532 1,2 %A A118532 _N. J. A. Sloane_, May 06 2006