The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A231115 Start with 1; then a(n+1) = concatenation of c(d) and d*c(d), where d is the last digit of a(n) and the counter c(d) is increased at each occurrence of d, and once more if d*c(d) would end in zero. 0
 1, 11, 22, 12, 24, 14, 28, 18, 216, 16, 212, 36, 318, 324, 312, 48, 432, 612, 714, 416, 424, 624, 728, 648, 756, 636, 742, 816, 848, 864, 832, 918, 972, 1122, 1224, 936, 954, 1144, 1248, 1188, 1296, 1166, 1272, 1326, 1378, 13104, 1352, 1428 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS The resulting sequence shows the multiplications that have been done, where the "," becomes the multiplication operator. E.g., ...,312,48,... shows that at this point the digit '2' occurred for the 4th time and the calculation was 2*4=8. At the next occurrence one would get 2 x 5 = 10 which is forbidden, so the counter is set to 6, which yields the 432,612 <=> 2*6=12. LINKS Table of n, a(n) for n=1..48. E. Angelini, Concatenating multiplications and successive results, post to SeqFan list, Nov 04 2013 PROG (PARI) c=vector(9); a=1; for(n=1, 99, print1(a", "); d=a%10; until(P%10, P=d*c[d]++); a=eval(Str(c[d], P))) CROSSREFS Sequence in context: A064263 A138838 A139337 * A040110 A140452 A048136 Adjacent sequences: A231112 A231113 A231114 * A231116 A231117 A231118 KEYWORD nonn,base AUTHOR Eric Angelini and M. F. Hasler, Nov 04 2013 STATUS approved

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 23 17:39 EDT 2024. Contains 372765 sequences. (Running on oeis4.)