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A207954 Palindromes with consecutive digits that differ exactly by 1. 2

%I #12 Feb 16 2021 14:18:32

%S 1,2,3,4,5,6,7,8,9,101,121,212,232,323,343,434,454,545,565,656,676,

%T 767,787,878,898,989,10101,12121,12321,21012,21212,23232,23432,32123,

%U 32323,34343,34543,43234,43434,45454,45654,54345,54545,56565,56765,65456,65656

%N Palindromes with consecutive digits that differ exactly by 1.

%H Reinhard Zumkeller, <a href="/A207954/b207954.txt">Table of n, a(n) for n = 1..10000</a>

%t Join[Range[9],Select[Range[70000],Union[Abs[Differences[ IntegerDigits[ #]]]] == {1}&&PalindromeQ[#]&]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Feb 16 2021 *)

%o (Haskell)

%o a207954 n = a207954_list !! (n-1)

%o a207954_list = filter ((== 1) . a136522) a033075_list

%Y Cf. A136522; intersection of A033075 and A002113.

%K nonn,base

%O 1,2

%A _Reinhard Zumkeller_, Feb 21 2012

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Last modified April 23 20:33 EDT 2024. Contains 371916 sequences. (Running on oeis4.)