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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A037279 If n is composite, replace n by the concatenation of its proper divisors, otherwise a(n) = n. 6
1, 2, 3, 2, 5, 23, 7, 24, 3, 25, 11, 2346, 13, 27, 35, 248, 17, 2369, 19, 24510, 37, 211, 23, 2346812, 5, 213, 39, 24714, 29, 23561015, 31, 24816, 311, 217, 57, 234691218, 37, 219, 313, 24581020, 41, 23671421, 43, 241122, 35915, 223, 47, 23468121624, 7 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

EXAMPLE

Divisors of 12 are 1,2,3,4,6,12, so a(12)=2346.

MAPLE

A037279 := proc(n) local dvs ; if isprime(n) or n = 1 then n; else dvs := [op(numtheory[divisors](n) minus {1, n} )] ; dvs := sort(dvs) ; cat(op(dvs)) ; fi ; end: seq(A037279(n), n=1..80) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 23 2007

CROSSREFS

Cf. A037278, A120712, A106708.

Sequence in context: A120716 A084318 A084317 * A163591 A085307 A078599

Adjacent sequences:  A037276 A037277 A037278 * A037280 A037281 A037282

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from Erich Friedman (erich.friedman(AT)stetson.edu).

Edited by N. J. A. Sloane (njas(AT)research.att.com), Aug 29 2008 at the suggestion of R. J. Mathar

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 .

Last modified February 14 19:37 EST 2012. Contains 205663 sequences.