A090323 Literal string created by the first time an orderless exponent appears; the exponents from A025487.

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

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