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A082907 A function applied to entries of Pascal-triangle as follows: C[n,j] is replaced by GCD[2^n,C[n,j]], providing largest power of 2 dividing C[n,j]. 2
1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 4, 2, 4, 1, 1, 1, 2, 2, 1, 1, 1, 2, 1, 4, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 8, 4, 8, 2, 8, 4, 8, 1, 1, 1, 4, 4, 2, 2, 4, 4, 1, 1, 1, 2, 1, 8, 2, 4, 2, 8, 1, 2, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 4, 2, 4, 1, 8, 4, 8, 1, 4, 2, 4, 1, 1, 1, 2, 2, 1, 1, 4, 4, 1, 1, 2, 2, 1, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

0,5

COMMENTS

If N is a power of 2, then then the first N rows are invariant under all 6 symmetries of an equilateral triangle. - Paul Boddington (psb(AT)maths.warwick.ac.uk), Dec 17 2003

FORMULA

T[n, j] = a[n]/(a[j]*a[n-j]) where a[n]=A060818[n]. T[n, j] = (b[j]*b[n-j])/b[n] where b[n]=A001316[n] (Gould's sequence). - Paul Boddington (psb(AT)maths.warwick.ac.uk), Dec 17 2003

EXAMPLE

Triangle read by rows:

1,

1,1,

1,2,1,

1,1,1,1,

1,4,2,4,1,

1,1,2,2,1,1,

1,2,1,4,1,2,1,

1,1,1,1,1,1,1,1,

1,8,4,8,2,8,4,8,1,

1,1,4,4,2,2,4,4,1,1,

n=-1+2^k: such rows consist of 1-s since all C[n,j]-s are odd.

MATHEMATICA

Flatten[Table[Table[GCD[2^n, Binomial[n, j]], {j, 0, n}], {n, 0, 25}], 1]

CROSSREFS

Cf. A000005, A007318, A000079.

Sequence in context: A205399 A135303 A036065 * A146532 A184879 A119335

Adjacent sequences:  A082904 A082905 A082906 * A082908 A082909 A082910

KEYWORD

nonn,tabl

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Apr 23 2003

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Last modified February 16 01:56 EST 2012. Contains 205860 sequences.