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

 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 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A004167 Powers of 3 written backwards. 16
 1, 3, 9, 72, 18, 342, 927, 7812, 1656, 38691, 94095, 741771, 144135, 3234951, 9692874, 70984341, 12764034, 361041921, 984024783, 7641622611, 1044876843, 30235306401, 90695018313, 72887134149, 184635924282, 344906882748, 9238285681452, 7894847955267 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS From a(2) onwards, all terms are divisible by 9. - Alonso del Arte, Apr 04 2014 LINKS Alois P. Heinz, Table of n, a(n) for n = 0..1000 FORMULA a(n) = A004086(A000244(n)). - Michel Marcus, Apr 05 2014 EXAMPLE a(5) = 342 since 3^5 = 243. MAPLE a:= n-> (s-> parse(cat(s[-i]\$i=1..length(s))))(""||(3^n)): seq(a(n), n=0..50); # Alois P. Heinz, Apr 09 2015 MATHEMATICA Table[FromDigits[Reverse[IntegerDigits[3^n]]], {n, 0, 26}] (* Alonso del Arte, Apr 04 2014 *) PROG (Python) def A004167(n): return int(str(3**n)[::-1]) # Chai Wah Wu, Feb 19 2021 CROSSREFS The following are parallel families: A000079 (2^n), A004094 (2^n reversed), A028909 (2^n sorted up), A028910 (2^n sorted down), A036447 (double and reverse), A057615 (double and sort up), A263451 (double and sort down); A000244 (3^n), A004167 (3^n reversed), A321540 (3^n sorted up), A321539 (3^n sorted down), A163632 (triple and reverse), A321542 (triple and sort up), A321541 (triple and sort down). Sequence in context: A084543 A318030 A018564 * A321539 A163632 A321541 Adjacent sequences: A004164 A004165 A004166 * A004168 A004169 A004170 KEYWORD nonn,base,easy AUTHOR EXTENSIONS More terms from Eric M. Schmidt, Apr 04 2014 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 December 3 11:24 EST 2022. Contains 358517 sequences. (Running on oeis4.)