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A127013 Triangle read by rows: reversal of A126988. +0
5
1, 1, 2, 1, 0, 3, 1, 0, 2, 4, 1, 0, 0, 0, 5, 1, 0, 0, 2, 3, 6, 1, 0, 0, 0, 0, 0, 7, 1, 0, 0, 0, 2, 0, 4, 8, 1, 0, 0, 0, 0, 0, 3, 0, 9, 1, 0, 0, 0, 0, 2, 0, 0, 5, 1, 0 (list; table; graph; listen)
OFFSET

1,3

COMMENT

Let j = reversed indices of row terms. Then for any row, j*T(n,k) = n, for non-zero T(n,k). For example, in row 10, we match the terms with their j indices: (1, 0, 0, 0, 0, 2, 0, 0, 5, 10), (dot product) (10, 9, 8, 7, 6, 5, 4, 3, 2, 1); getting 10, 0, 0, 0, 0, 10, 0, 0, 10, 10). The factors of n are found in each row in order, as non-zero terms; e.g. 10 has the factors 1, 2, 5, 10, sum 18. Row sums = sigma(n), A000203.

REFERENCES

David Wells, "Prime Numbers, The Most Mysterious Figures in Math", John Wiley & Sons, 2005, Appendix.

FORMULA

Reversed rows of A126988

EXAMPLE

Row 10 = (1, 0, 0, 0, 0, 2, 0, 0, 5, 10), reversal of 10-th row of A126988.

CROSSREFS

Cf. A126988, A000203.

Sequence in context: A063173 A120111 A130055 this_sequence A117362 A113214 A029323

Adjacent sequences: A127010 A127011 A127012 this_sequence A127014 A127015 A127016

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 02 2007

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Last modified September 7 15:23 EDT 2008. Contains 143483 sequences.


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