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 A007398 M4422 #22 Aug 01 2018 02:48:13 %S A007398 0,7,41,84,19,62,96,301,803,18,52,95,201,802,908,519,625,236,342,943, %T A007398 59,66,37,44,15,22,92,99,601,806,318,523,35,24,13,2,9,61,86,39,64,17, %U A007398 42,94,101,801,808,518,525,235,242,942,949,659,666,376,383,93,1,8,51,85,29,63 %N A007398 Add 7, then reverse digits. %C A007398 From n = 1 the sequence is periodic with a period of 63. The Data without the initial 0 gives that period. - _David A. Corneth_, Aug 01 2018 %D A007398 J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 15. %D A007398 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A007398 Vincenzo Librandi, <a href="/A007398/b007398.txt">Table of n, a(n) for n = 0..1000</a> %H A007398 Nick Hobson, <a href="/A007398/a007398.py.txt">Python program for this sequence</a> %H A007398 N. J. A. Sloane and others, <a href="/wiki/Sequences_of_RADD_type">Sequences of RADD type</a>, OEIS wiki. %p A007398 rev:=proc(n) local nn, nnn: nn:=convert(n,base,10): add(nn[nops(nn)+1-j]*10^(j-1),j=1..nops(nn)) end: a[0]:=0: for n from 1 to 70 do a[n]:=rev(7+a[n-1]) od: seq(a[n],n=0..70); # _Emeric Deutsch_, Jul 28 2006 %t A007398 NestList[FromDigits[Reverse[IntegerDigits[# + 7]]]&, 0, 60] (* _Vincenzo Librandi_, Aug 08 2017 *) %o A007398 (PARI) first(n) = my(res = vector(n)); res[1]=0; for(i = 2, n, res[i] = fromdigits(Vecrev(digits(res[i - 1] + 7)))); res \\ _David A. Corneth_, Aug 01 2018 %Y A007398 Cf. A117828. %K A007398 nonn,base,easy %O A007398 0,2 %A A007398 _N. J. A. Sloane_ %E A007398 More terms from _Emeric Deutsch_, Jul 28 2006