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A008781 For any circular arrangement of 0..n-1, let S = sum of cubes of every sum of two contiguous numbers; then a(n) = # of distinct values of S. 0
1, 1, 1, 3, 12, 46, 163, 405, 770, 1252, 1921 (list; graph; refs; listen; history; internal format)
OFFSET

1,4

EXAMPLE

Consider n = 12: and the circular arrangements of {0,1,2,3,4}. Here are the values of [ A, B, C, D, E ] (A+B)^3 + (B+C)^3 +(C+D)^3 +(D+E)^3 +(E+A)^3:

[0,1,2,3,4], (0+1)^3 + (1+2)^3 +(2+3)^3 +(3+4)^3 +(4+0)^3 = 560;

[0,1,2,4,3], (0+1)^3 + (1+2)^3 +(2+4)^3 +(4+3)^3 +(3+0)^3 = 614;

[0,1,3,2,4], (0+1)^3 + (1+3)^3 +(3+2)^3 +(2+4)^3 +(4+0)^3 = 470;

[0,1,4,2,3], (0+1)^3 + (1+4)^3 +(4+2)^3 +(2+3)^3 +(3+0)^3 = 494;

[0,1,3,4,2], (0+1)^3 + (1+3)^3 +(3+4)^3 +(4+2)^3 +(2+0)^3 = 632;

[0,1,4,3,2], (0+1)^3 + (1+4)^3 +(4+3)^3 +(3+2)^3 +(2+0)^3 = 602;

[0,2,1,3,4], (0+2)^3 + (2+1)^3 +(1+3)^3 +(3+4)^3 +(4+0)^3 = 506;

[0,2,1,4,3], (0+2)^3 + (2+1)^3 +(1+4)^3 +(4+3)^3 +(3+0)^3 = 530;

[0,3,1,2,4], (0+3)^3 + (3+1)^3 +(1+2)^3 +(2+4)^3 +(4+0)^3 = 398;

[0,4,1,2,3], (0+4)^3 + (4+1)^3 +(1+2)^3 +(2+3)^3 +(3+0)^3 = 368;

[0,3,1,4,2], (0+3)^3 + (3+1)^3 +(1+4)^3 +(4+2)^3 +(2+0)^3 = 440;

[0,4,1,3,2], (0+4)^3 + (4+1)^3 +(1+3)^3 +(3+2)^3 +(2+0)^3 = 386;

There are 12 different values, so a(5) = 12.

CROSSREFS

Cf. A007773, A008782.

Sequence in context: A026559 A188949 A184699 * A047013 A108368 A176310

Adjacent sequences:  A008778 A008779 A008780 * A008782 A008783 A008784

KEYWORD

nonn

AUTHOR

Olivier Gerard (olivier.gerard(AT)gmail.com)

EXTENSIONS

Corrected by Naohiro Nomoto (n_nomoto(AT)yabumi.com), Sep 10 2001

More terms from Vit Planocka (planocka(AT)mistral.cz), Sep 29 2002

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Last modified February 17 13:28 EST 2012. Contains 206031 sequences.