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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A090323 Literal string created by the first time an orderless exponent appears; the exponents from A025487. 0
1, 2, 11, 3, 21, 4, 31, 111, 5, 22, 41, 211, 6, 32, 51, 311, 7, 42, 221, 61, 1111, 33, 411, 8, 52, 321, 71, 2111, 43, 511, 9, 62, 421, 81, 3111, 53, 222, 611, 10, 331, 72, 2211, 44, 521, 91, 4111, 63, 322, 711, 11, 431, 82, 11111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

There is a pattern to this, compare the values between 7 and 8 and 8 and 9 for example.

LINKS

Table of n, a(n) for n=1..53.

EXAMPLE

The sequence corresponds to 2(1), 4(2), 6(11), 8(3), 12(21), 16(4). 18 is counted as (21) and so does not appear.

PROG

(PARI) { v=[2, 4, 6, 8, 12, 16, 24, 30, 32, 36, 48, 60, 64, 72, 96, 120, 128, 144, 180, 192, 210, 216, 240, 256, 288, 360, 384, 420, 432, 480, 512, 576, 720, 768, 840, 864, 900, 960, 1024, 1080, 1152, 1260, 1296, 1440, 1536, 1680, 1728, 1800, 1920, 2048, 2160, 2304, 2310]; for (i=1, length(v), print1(", "); for (j=1, length(factor(v[i])[, 2]), print1(factor(v[i])[j, 2]))) }

CROSSREFS

Cf. A025487.

Sequence in context: A110741 A113625 A279237 * A127668 A261300 A068743

Adjacent sequences:  A090320 A090321 A090322 * A090324 A090325 A090326

KEYWORD

nonn

AUTHOR

Jon Perry, Jan 26 2004

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 19 22:32 EDT 2019. Contains 323411 sequences. (Running on oeis4.)