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A239446 Triangle read by rows: T(n,k), n>=1, k>=1, in which column k lists the elements of A004273 interleaved with k zeros, and the first element of column k is in row k*(k+1)/2. 2
0, 0, 1, 0, 0, 0, 3, 0, 0, 1, 0, 5, 0, 0, 0, 0, 0, 7, 3, 0, 0, 0, 1, 0, 9, 0, 0, 0, 0, 5, 0, 0, 11, 0, 0, 0, 0, 0, 3, 0, 13, 7, 0, 1, 0, 0, 0, 0, 0, 0, 15, 0, 0, 0, 0, 0, 9, 5, 0, 0, 17, 0, 0, 0, 0, 0, 0, 0, 3, 0, 19, 11, 0, 0, 1, 0, 0, 0, 7, 0, 0, 0, 21, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,7

COMMENTS

Alternating sum of row n equals A235796(n), i.e., sum_{k=1..A003056(n)} (-1)^(k-1)*T(n,k) = A235796(n).

Row n has length A003056(n) hence column k starts in row A000217(k).

Column k starts with k+1 zeros and then lists the odd numbers interleaved with k zeros.

It appears that row n lists all zeros iff n is a power of 2.

LINKS

Table of n, a(n) for n=1..84.

EXAMPLE

Triangle begins:

0;

0;

1,  0;

0,  0;

3,  0;

0,  1,  0;

5,  0,  0;

0,  0,  0;

7,  3,  0;

0,  0,  1,  0;

9,  0,  0,  0;

0,  5,  0,  0;

11, 0,  0,  0;

0,  0,  3,  0;

13, 7,  0,  1,  0;

0,  0,  0,  0,  0;

15, 0,  0,  0,  0;

0,  9,  5,  0,  0;

17, 0,  0,  0,  0;

0,  0,  0,  3,  0;

19, 11, 0,  0,  1,  0;

0,  0,  7,  0,  0,  0;

21, 0,  0,  0,  0,  0;

0,  13, 0,  0,  0,  0;

23, 0,  0,  5,  0,  0;

...

For n = 15 the 15th row of triangle is 13, 7, 0, 1, and the alternating sum is 13 - 7 + 0 - 1 = A235796(15) = 5.

CROSSREFS

Cf. A000203, A000217, A003056, A004125, A004273, A196020, A231345, A231347, A235791, A235794, A235796, A236106, A236104, A236112, A237048, A237588, A237591, A239313.

Sequence in context: A171913 A074936 A035655 * A036857 A318508 A100655

Adjacent sequences:  A239443 A239444 A239445 * A239447 A239448 A239449

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Mar 20 2014

STATUS

approved

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Last modified September 17 08:31 EDT 2019. Contains 327127 sequences. (Running on oeis4.)