A299693 - OEIS

A299693

Irregular triangle read by rows in which row n lists the total sum of the divisors of all numbers k such that the largest Dyck path of the symmetric representation of sigma(k) contains the point (n,n); or row n is 0 if no such k exists.

1, 3, 4, 7, 6, 0, 12, 8, 15, 13, 18, 12, 0, 28, 14, 24, 0, 24, 31, 18, 39, 20, 0, 42, 32, 36, 24, 0, 60, 31, 42, 40, 0, 56, 30, 0, 72, 32, 63, 48, 54, 0, 48, 91, 38, 60, 56, 0, 90, 42, 0, 96, 44, 84, 0, 78, 72, 48, 0, 124, 57, 93, 72, 98, 54, 0, 120, 72, 0, 120, 80, 90, 60, 0, 168, 62, 96, 0, 104, 127, 84, 0

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OFFSET

1,2

LINKS

Table of n, a(n) for n=1..82.

FORMULA

T(n,m) = A000203(A279385(n,m) if A279385(n,m) > 0, otherwise T(n,m) = 0.

EXAMPLE

Triangle begins:

3, 4;

7, 6;

12, 8;

15;

13, 18, 12;

28, 14, 24;

24;

31, 18;

39, 20;

42, 32, 36, 24;

...

CROSSREFS

Nonzero terms give A000203.

Row sums give A299472.

Cf. A259179(n) is the number of positive terms in row n.

Cf. A071562, A196020, A235791, A236104, A237048, A237591, A237593, A240542, A244050, A245092, A276112, A277437, A279286, A279385, A280919, A280223, A282131, A282197, A280295, A281012.

Sequence in context: A285896 A082226 A010613 * A134688 A077650 A244669

Adjacent sequences: A299690 A299691 A299692 * A299694 A299695 A299696

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Feb 19 2018

STATUS

approved