The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A290148 a(n) is the integer resulting from the concatenation of the unit digit of n-1 to the digits of n without its own unit digit. 0

%I

%S 0,1,2,3,4,5,6,7,8,91,1,11,21,31,41,51,61,71,81,92,2,12,22,32,42,52,

%T 62,72,82,93,3,13,23,33,43,53,63,73,83,94,4,14,24,34,44,54,64,74,84,

%U 95,5,15,25,35,45,55,65,75,85,96,6,16,26,36,46,56,66,76,86,97,7

%N a(n) is the integer resulting from the concatenation of the unit digit of n-1 to the digits of n without its own unit digit.

%C Take list of integers n >= 1, move right digit of each term to left end of next term.

%F a(n) = (n -1 mod 10)*10^A004216(n) + floor(n/10). # _Robert Israel_, Jul 21 2017

%e For n=46, n-1 is 45, so a(46) is the concatenation of 5 (the unit digit of 45) and 4 (46 without 6), giving 54.

%e For n=123, n-1 is 122, so a(123) is the concatenation of 2 (the unit digit of 122) and 12 (123 without 3), giving 212.

%p f:= n -> (n-1 mod 10) * 10^ilog10(n) + floor(n/10);

%o (PARI) a(n) = my(precd = (n-1)%10); if (n < 10, precd, eval(concat(Str(precd), Str(n\10))));

%Y Cf. A004216, A032762.

%K nonn,base

%O 1,3

%A _Michel Marcus_, Jul 21 2017

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified May 27 16:48 EDT 2022. Contains 354110 sequences. (Running on oeis4.)