This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A061229 Floor of geometric mean of n and the reversal of n. 3
 1, 2, 3, 4, 5, 6, 7, 8, 9, 3, 11, 15, 20, 23, 27, 31, 34, 38, 41, 6, 15, 22, 27, 31, 36, 40, 44, 47, 51, 9, 20, 27, 33, 38, 43, 47, 51, 56, 60, 12, 23, 31, 38, 44, 49, 54, 58, 63, 67, 15, 27, 36, 43, 49, 55, 60, 65, 70, 74, 18, 31, 40, 47, 54, 60, 66, 71, 76, 81, 22, 34, 44 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harry J. Smith, Table of n, a(n) for n=1,...,2000 FORMULA a(n) = floor[ {n * R(n)}^(1/2)], where R(n)= the digit reversal of n (A004086). EXAMPLE a(15)=floor(sqrt(15*51))=floor(sqrt(765))=27. PROG (PARI) { default(realprecision, 100); for (n=1, 2000, x=n; r=0; while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); write("b061229.txt", n, " ", floor(sqrt(n*r))) ) } [From Harry J. Smith, Jul 19 2009] CROSSREFS Cf. A079827. Sequence in context: A028898 A081502 A079828 * A122666 A114288 A028899 Adjacent sequences:  A061226 A061227 A061228 * A061230 A061231 A061232 KEYWORD nonn,base AUTHOR Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 23 2001 EXTENSIONS Edited by N. J. A. Sloane, Jan 17 2009 at the suggestion of R. J. Mathar STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .