%I #54 Nov 17 2022 14:15:56
%S 0,2,4,6,8,10,12,14,16,18,11,22,33,44,55,66,77,88,99,110,22,33,44,55,
%T 66,77,88,99,110,121,33,44,55,66,77,88,99,110,121,132,44,55,66,77,88,
%U 99,110,121,132,143,55,66,77,88,99,110,121,132,143,154,66,77,88,99,110
%N a(n) = n + reversal of digits of n.
%C If n has an even number of digits then a(n) is a multiple of 11.
%C Also called the Reverse and Add!, or RADD operation. Iteration of this function leads to the definition of Lychrel and related numbers, cf. A023108, A063048, A088753, A006960, and many others. - _M. F. Hasler_, Apr 13 2019
%H Indranil Ghosh, <a href="/A056964/b056964.txt">Table of n, a(n) for n = 0..20000</a> (first 1001 terms from T. D. Noe)
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Reverse-Then-AddSequence.html">Reverse-Then-Add Sequence</a>
%H <a href="/index/Res#RAA">Index entries for sequences related to Reverse and Add!</a>
%F a(n) = n + A004086(n) = 2*n - A056965(n).
%F n < a(n) < 11n for n > 0. - _Charles R Greathouse IV_, Nov 17 2022
%e a(17) = 17 + 71 = 88.
%t Table[n+FromDigits[Reverse[IntegerDigits[n]]],{n,0,100}] (* _Harvey P. Dale_, Jul 19 2014 *)
%o (Haskell) a056964 n = n + a004086 n -- _Reinhard Zumkeller_, Oct 14 2011
%o (PARI) A056964(n)=fromdigits(Vecrev(digits(n)))+n \\ _Charles R Greathouse IV_, Oct 28 2014
%o (Python) def A056964(n): return n+int(str(n)[::-1]) # _Indranil Ghosh_, Jan 29 2017
%Y Cf. A004086, A056965, A067030.
%Y Differs from A052008 when n=101 and a(101)=202 while A052008(101)=121
%Y Cf. A036839.
%K nonn,base,easy
%O 0,2
%A _Henry Bottomley_, Jul 18 2000