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A215605
Number of unordered interval sequences that sum up to 12n in Schoenberg 12-tone rows.
0
1, 36, 798, 4507, 11470, 15407, 11470, 4507, 798, 36, 1
OFFSET
1,2
COMMENTS
A Schoenberg 12-tone row is a permutation of the integers from 0 to 11. It is assumed the first element is 0 so there are 11! 12-tone rows. The unordered interval sequence is the 1st-order difference modulo 12 arranged into a sorted list.
REFERENCES
Ole Kirkeby, Interval Sequences In 12-Tone Rows, to be submitted to Online Journal of Integer Sequences.
EXAMPLE
There is only one unordered interval sequence whose sum is 12, and it contains all ones. One of the 36 that sums up to 2*12=24 is [1,1,1,1,1,1,1,1,1,2,2,11], and one of the 798 that sums up to 3*12=36 is [1,1,1,1,1,1,1,1,3,3,11,11].
CROSSREFS
Sequence in context: A014772 A110206 A133051 * A173187 A028222 A028216
KEYWORD
nonn,fini,full
AUTHOR
Ole Kirkeby, Aug 17 2012
STATUS
approved