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A140820 Triangle read by rows: let c(i,k)=Floor[Mod[i/2^k, 2]]; b(i,k)=If[c[i, k] == 0 && c[i, k + 1] == 0, 0, If[c[ i, k] == 1 && c[i, k + 1] ==1, 0, 1]]; then t(i,j)=If[Sum[b[i, k]*b[j, k], {k, 0, n}] == 0, 1, 0]. +0
2
1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 (list; table; graph; listen)
OFFSET

1,1

COMMENT

Row sums are: {1, 1, 1, 2, 2, 1, 2, 4, 4, 2, 1, 2, 4, 2, 4, 8, 8, ...}.

In this method the information is complete: as it is a symbol representation instead of {0,1}, {-1,1} or {1,2} can be used in the output just as well.

This kind of code is used in minimal coding representations like the binary Gray code.

FORMULA

c(i,k)=Floor[Mod[i/2^k, 2]]; b(i,k)=If[c[i, k] == 0 && c[i, k + 1] == 0, 0, If[c[ i, k] == 1 && c[i, k + 1] ==1, 0, 1]]; t(i,j)=If[Sum[b[i, k]*b[j, k], {k, 0, n}] == 0, 1, 0].

EXAMPLE

{1},

{1, 0},

{1, 0, 0},

{1, 1, 0, 0},

{1, 1, 0, 0, 0},

{1, 0, 0, 0, 0, 0},

{1, 0, 0, 1, 0, 0, 0},

{1, 1, 1, 1, 0, 0, 0, 0},

{1, 1, 1, 1, 0, 0, 0, 0, 0},

{1, 0, 0, 1, 0, 0, 0, 0, 0, 0},

{1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},

{1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},

{1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0},

{1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0},

{1, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0},

{1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0},

{1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}

MATHEMATICA

Clear[c, b, n, a0, d] c[i_, k_] := Floor[Mod[i/2^k, 2]]; b[i_, k_] = If[c[i, k] == 0 && c[i, k + 1] == 0, 0, If[c[ i, k] == 1 && c[i, k + 1] == 1, 0, 1]]; n = 16; a0 = Table[Table[If[Sum[b[i, k]*b[j, k], {k, 0, n}] == 0, 1, 0], {j, 0, i}], {i, 0, n}]; Flatten[a0]

CROSSREFS

Cf. A131218.

Sequence in context: A055088 A068427 A164057 this_sequence A167501 A147612 A080545

Adjacent sequences: A140817 A140818 A140819 this_sequence A140821 A140822 A140823

KEYWORD

nonn,tabl

AUTHOR

Roger L. Bagula and Gary W. Adamson (rlbagulatftn(AT)yahoo.com), Oct 17 2008

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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