A015976 One iteration of Reverse and Add is needed to reach a palindrome.

1, 2, 3, 4, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26, 27, 29, 30, 31, 32, 33, 34, 35, 36, 38, 40, 41, 42, 43, 44, 45, 47, 50, 51, 52, 53, 54, 56, 60, 61, 62, 63, 65, 70, 71, 72, 74, 80, 81, 83, 90, 92, 100, 101, 102, 103, 104, 105, 106

Offset

1,2

Comments

The number of iterations starts at 1, so palindromes (cf. A002113) are not excluded. The corresponding sequence excluding palindromes is A065206.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for sequences related to Reverse and Add!

Mathematica

rev[n_] := FromDigits[Reverse[IntegerDigits[n]]]; Select[Range[106], rev[x = # + rev[#]] == x &] (* Jayanta Basu, Jul 24 2013 *)
Select[Range[120], PalindromeQ[#+IntegerReverse[#]]&] (* Harvey P. Dale, Jul 04 2022 *)

Prog

(Haskell)
a015976 n = a015976_list !! (n-1)
a015976_list = filter ((== 1) . a136522 . a056964) [1..]
-- Reinhard Zumkeller, Oct 14 2011

Crossrefs

Cf. A002113, A065206.

Sequence in context: A054930 A329230 A119798 * A370842 A098892 A174139

Adjacent sequences: A015973 A015974 A015975 * A015977 A015978 A015979

Keyword

nonn,base,look

Author

Robert G. Wilson v

Extensions

Offset corrected by Reinhard Zumkeller, Oct 14 2011

Status

approved