OFFSET
0,2
COMMENTS
If n has an even number of digits then a(n) is a multiple of 11.
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
LINKS
Indranil Ghosh, Table of n, a(n) for n = 0..20000 (first 1001 terms from T. D. Noe)
Eric Weisstein's World of Mathematics, Reverse-Then-Add Sequence
FORMULA
n < a(n) < 11n for n > 0. - Charles R Greathouse IV, Nov 17 2022
EXAMPLE
a(17) = 17 + 71 = 88.
MATHEMATICA
Table[n+FromDigits[Reverse[IntegerDigits[n]]], {n, 0, 100}] (* Harvey P. Dale, Jul 19 2014 *)
PROG
(Haskell) a056964 n = n + a004086 n -- Reinhard Zumkeller, Oct 14 2011
(PARI) A056964(n)=fromdigits(Vecrev(digits(n)))+n \\ Charles R Greathouse IV, Oct 28 2014
(Python) def A056964(n): return n+int(str(n)[::-1]) # Indranil Ghosh, Jan 29 2017
CROSSREFS
KEYWORD
nonn,base,easy,changed
AUTHOR
Henry Bottomley, Jul 18 2000
STATUS
approved