Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #13 Dec 24 2017 15:59:09
%S 0,1,2,3,4,5,6,7,8,9,10,12,21,23,32,34,43,45,54,56,65,67,76,78,87,89,
%T 98,131,135,202,242,246,313,353,357,420,424,464,468,531,535,575,579,
%U 642,646,686,753,757,797,864,868,975,979,1414,1474,2525,2585,3030,3036,3630,3636,3696,4141,4147,4741,4747,5252,5258,5852,5858,6303,6363,6369,6963,6969,7414,7474,8525,8585,9630,9636,9696,15151,15159,15951,15959,26262,37373,40404,40484,48404,48484,51515,51595,59515,59595,62626,73737,84040,84048,84840,84848,95151,95159,95951,95959,161616,272727,383838,494949,505050,616161,727272,838383,949494,1717171,2828282,3939393,6060606,7171717,8282828,9393939,18181818,29292929,70707070,81818181,92929292,191919191,808080808,919191919,9090909090
%N List of numbers k whose consecutive digits increase or decrease by d-1, where d is the number of digits in k.
%C Finite, 131 terms.
%t Range[0, 9]~Join~Select[Union[Range[10^5], Flatten@ Map[Map[FromDigits /@ {Drop[#, -1], #} &, Table[Flatten@ ConstantArray[#, k], {k, 3, 5}]] &, IntegerDigits@ Range[10, 99]]], If[Length@ #1 == 1, First@ #1 == #2 - 1, False] & @@ {Union@ Abs@ Differences@ #, Length@ #} &@ IntegerDigits[#] &] (* _Michael De Vlieger_, Dec 09 2017 *)
%o (PARI) is(n) = for(i=2, #n=digits(n), if(abs(n[i]-n[i-1]) != #n-1, return(0))); 1 \\ _Iain Fox_, Dec 08 2017
%K nonn,base,fini,full
%O 1,3
%A _Enrique Navarrete_, Dec 08 2017