The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A342157 Base-10 numbers m such that k*m = d||d||...||d (here || appears k-1 times), where k is the length of m, d is any m's digit and || represents concatenation. 0
 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 148, 185, 148148 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS All numbers satisfying such conditions must be smaller than 10^9, because if we take any 10-digit number m, 10m is an 11-digit number while d||d||...||d is a 10-digit number. 148 and 148148 are the only numbers in the sequence for which d is not necessarily the last digit (for 148 we take d=4, which is the second digit of 148 and for 148148 we take d=8, which is the last, but also the third digit). LINKS EXAMPLE m=148 is in the sequence, because if we multiply 148 by k=3 (length of 148) we obtain 444, which is d||d||d for d=4 (second digit of 148) PROG (C++) #include #include using namespace std; int length(int a){for(int i=0; i<=10; i++){if(pow(10, i)<=a && pow(10, i+1)>a){return i+1; }}} int DC(int a, int b){int c=(a%(int)(pow(10, b))-a%(int)(pow(10, b-1)))/(int)(pow(10, b-1)); int l=length(a); int s=0; for(int i=0; i

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

Last modified September 20 16:50 EDT 2021. Contains 347586 sequences. (Running on oeis4.)