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

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A132361 A ten-out-of-twelve fractal substitution sequence based on 7th like chords: 1->{1,5,9,12}->{A,Db,F,Ab}, 3->{3,7,11,2}->{B,E, G,Bb}, 4->{4,8,12,3}->{C,Eb,Ab,B}. 0
11, 7, 3, 2, 12, 8, 4, 3, 3, 4, 12, 8, 8, 3, 4, 12, 12, 9, 5, 1, 9, 1, 5, 12, 3, 4, 12, 8, 1, 5, 12, 9, 1, 5, 12, 9, 12, 9, 5, 1, 9, 1, 5, 12, 3, 4, 12, 8, 3, 4, 12, 8, 1, 5, 12, 9, 9, 1, 5, 12, 12, 9, 5, 1, 2, 11, 7, 3, 2, 2, 3, 11, 7, 7, 2, 3, 11, 7, 2, 3, 11, 2, 11, 7, 3, 2, 2, 3, 11, 7, 2, 3, 11, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence uses nine basic tones with {2}->Bb as a terminator. If the triad chords are used only it has less of a blue sound and only has nine tones. It also goes from 4!=24 permutations possible to 3!=6: that significantly lowers the possible out comes for automated output. Substitutions with the permutations increase the variability of this type of sequence.

LINKS

Table of n, a(n) for n=1..94.

FORMULA

Substitution function that skip {6,10} and use {2} as a terminator:

s[1] = {12, 9, 5, 1};

s[2] = {2};

s[3] = {11, 7, 3, 2};

s[4] = {12, 8, 4, 3};

s[5] = Permutations[s[1]][[12]];

s[6] = {6};

s[7] = Permutations[s[3]][[12]]; s[8] = Permutations[s[4]][[12]];

s[9] = Permutations[s[1]][[23]];

s[10] = {10};

s[11] = Permutations[s[3]][[23]];

s[12] = Permutations[s[4]][[23]];

Permutations {12,23} are used for spread, but any two combinations of 24:Binomial[24,2]=46 can be used if the first substitutions are the reference state.

MATHEMATICA

Clear[s]

s[1] = {12, 9, 5, 1};

s[2] = {2};

s[3] = {11, 7, 3, 2};

s[4] = {12, 8, 4, 3};

s[5] = Permutations[s[1]][[12]];

s[6] = {6};

s[7] = Permutations[s[3]][[12]]; s[8] = Permutations[s[4]][[12]];

s[9] = Permutations[s[1]][[23]];

s[10] = {10};

s[11] = Permutations[s[3]][[23]];

s[12] = Permutations[s[4]][[23]];

t[a_] := Flatten[s /@ a]; p[0] = {1, 3, 4}; p[1] = t[p[0]];

p[n_] := t[p[n - 1]];

p[3]

CROSSREFS

Cf. A132150, A132160.

Sequence in context: A005603 A109828 A048981 * A236546 A155914 A087896

Adjacent sequences:  A132358 A132359 A132360 * A132362 A132363 A132364

KEYWORD

nonn,uned

AUTHOR

Roger L. Bagula, Nov 08 2007, Nov 09 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified December 18 02:14 EST 2014. Contains 252068 sequences.