login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061205 a(n) = n times R(n) where R(n) (A004086) is the digit reversal of n. 11
0, 1, 4, 9, 16, 25, 36, 49, 64, 81, 10, 121, 252, 403, 574, 765, 976, 1207, 1458, 1729, 40, 252, 484, 736, 1008, 1300, 1612, 1944, 2296, 2668, 90, 403, 736, 1089, 1462, 1855, 2268, 2701, 3154, 3627, 160, 574, 1008, 1462, 1936, 2430, 2944, 3478, 4032, 4606 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Every third term is divisible by 9, no other term is divisible by 3. - Alonso del Arte, Mar 04 2013

LINKS

Harry J. Smith and Indranil Ghosh, Table of n, a(n) for n = 0..10000 (first 1001 terms from Harry J. Smith)

EXAMPLE

a(10) = 10 = 10 * 01.

a(11) = 121 = 11 * 11.

a(12) = 252 = 12 * 21.

a(13) = 403 = 13 * 31.

MATHEMATICA

#*FromDigits[Reverse[IntegerDigits[#]]] &/@Range[0, 49]  (* Ant King, Jan 07 2012 *)

PROG

(PARI) { for (n=0, 1000, x=n; r=0; while (x>0, d=x-10*(x\10); x\=10; r=r*10 + d); write("b061205.txt", n, " ", n*r) ) } \\ Harry J. Smith, Jul 18 2009

(PARI) rev(k) = subst(Polrev(digits(k)), x, 10);

a(n) = n*rev(n); \\ Michel Marcus, Feb 14 2015

(Haskell)

a061205 n = a004086 n * n

-- Reinhard Zumkeller, Apr 10 2012, Apr 29 2011

(Python)

def A061205(n):

    return n*A004086(n) # Indranil Ghosh, Jan 09 2017

CROSSREFS

Cf. A203924 for triple repetitions.

Sequence in context: A230101 A057147 A213630 * A048387 A035121 A080151

Adjacent sequences:  A061202 A061203 A061204 * A061206 A061207 A061208

KEYWORD

nonn,base,look

AUTHOR

Amarnath Murthy, Apr 21 2001

EXTENSIONS

Corrected and extended by Patrick De Geest, Jun 04 2001

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified April 25 15:43 EDT 2017. Contains 285416 sequences.