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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A193381 Largest multiple of n which is a concatenation of the n numbers n(n-1)/2,...,n(n+1)/2-1, or 0 if no such number exists. 0
0, 12, 543, 9876, 1413121110, 201918171516, 27262524212322, 3534333231302928, 444342414039383736, 54535251494847464550, 6564636261605958575655, 777675747372717069676668, 90898887868584838281798078, 999897969594939291104103101102100 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is to A192392 what is A080481 to A053067: The integers are considered in groups of n=1,2,3,... numbers, starting with {0}, {1,2}, {3,4,5}, ... The sequence lists the concatenation of the permutation of the n elements of each group which yields the largest multiple of n, when written in decimal.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

a(20) = concat(210,209,...,201,199,...,191,200).

PROG

(PARI) a(n)={my(d=vecsort(vector(n, i, Str(n*(n-1)/2-1+i)), , 4), t); for(i=1, n!, eval(concat(d))%n || return(eval(concat(d))); d=precperm(d))} /* see A076072 for precperm() */

CROSSREFS

Sequence in context: A184423 A064344 A163046 * A224539 A210816 A133415

Adjacent sequences:  A193378 A193379 A193380 * A193382 A193383 A193384

KEYWORD

nonn,base

AUTHOR

M. F. Hasler, Jul 24 2011

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 25 12:30 EDT 2019. Contains 323568 sequences. (Running on oeis4.)