This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A123872 Start with the seed a(0)=2. The minimum number, different from 1, that multiplied by 2 (seed) produces a number with 2 as its rightmost digit is a(1)=6. Then 6*2=12. Again, the minimum number that multiplied by 12 produces 12 as its rightmost digits is a(2)=26 (12*26=312). And so on. 3
 2, 6, 26, 126, 6251, 62500001 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 99. LINKS EXAMPLE a(0)=2; a(1)=6 because 2*6 = 12; a(2)=26 because 12*26 = 312; a(3)=126 because 312*126 = 39312; a(4)=6251 because 39312*6251 = 245739312; a(5)=62500001 because 245739312*62500001 = 15358707245739312. MAPLE P:=proc(q, h) local a, b, k, n; a:=h; b:=ilog10(a)+1; print(h); for k from 1 to 10 do for n from 2 to q do if ((a*n) mod 10^b)=a then print(n); a:=a*n; b:=ilog10(a)+1; break; fi; od; od; end: P(10^9, 2); CROSSREFS Cf. A123873-A123875. Sequence in context: A192808 A034474 A306041 * A230071 A030937 A030827 Adjacent sequences:  A123869 A123870 A123871 * A123873 A123874 A123875 KEYWORD nonn,base,more AUTHOR Paolo P. Lava and Giorgio Balzarotti, Oct 16 2006 STATUS approved

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 August 20 22:45 EDT 2019. Contains 326155 sequences. (Running on oeis4.)