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Search: id:A120769
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A120769 Dot product sequence, with reversed subsets. +0
2
1, 1, 2, 1, 4, 6, 2, 1, 8, 14, 36, 20, 4, 6, 2, 1, 16, 30, 84, 52, 240, 396, 140, 72, 8, 14, 36, 20, 4, 6, 2, 1 (list; graph; listen)
OFFSET

1,3

COMMENT

A120405 = a dot product sequence, with no reversals. A120770 = partial sums of A120769.

FORMULA

a(1) = 1; then perform n * a(n) on each term in the current string; reverse the order and append to right of current string.

EXAMPLE

a(1) = 1, a(2) = 1, then perform the dot product of (1, 2) and (1, 1) getting (1, 2). We reverse (1, 2) getting (2, 1) which we append to the right of the current string (1, 1), getting (1, 1, 2, 1) for a(1) through a(4). Next, perform the dot product of (1, 2, 3, 4) and (1, 1, 2, 1) getting (1, 2, 6, 4) which we reverse, =

(4, 6, 2, 1). Append to the current string (1, 1, 2, 1), getting (1, 1, 2, 1, 4, 6, 2, 1) for a(1) through a(8). Continue with analogous operations.

CROSSREFS

Cf. A120405, A120768, A120770.

Sequence in context: A079474 A091543 A059575 this_sequence A111932 A121456 A127535

Adjacent sequences: A120766 A120767 A120768 this_sequence A120770 A120771 A120772

KEYWORD

nonn,uned

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jul 03 2006

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Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


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