

A271668


Triangle read by rows. The first column is A000217(n+1). From the second row we apply  A002262(n) for the following terms of the row.


1



1, 3, 3, 6, 6, 5, 10, 10, 9, 7, 15, 15, 14, 12, 9, 21, 21, 20, 18, 15, 11, 28, 28, 27, 25, 22, 18, 13, 36, 36, 35, 33, 30, 26, 21, 15, 45, 45, 44, 42, 39, 35, 30, 24, 17, 55, 55, 54, 52, 49, 45, 40, 34, 27, 19, 66, 66, 65, 63, 60, 56, 51, 45, 38, 30, 21
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OFFSET

0,2


COMMENTS

Row sums: A084990(n+1).
A158405(n) = A002262(n) + A002260(n). See the formula.
(Without its first column, A094728 is A120070, which could be built from positive A005563 and A158894.)


LINKS

Table of n, a(n) for n=0..65.


FORMULA

a(n) = A094728(n+1)  A049780(n).


EXAMPLE

a(0) = 1, a(1) = 3, a(2) =30 = 3, a(3) = 6, a(4) =60= 6, a(5) =61= 5, ... .
Triangle:
1,
3, 3,
6, 6, 5,
10, 10, 9, 7,
15, 15, 14, 12, 9,
21, 21, 20, 18, 15, 11,
28, 28, 27, 25, 22, 18, 13,
36, 36, 35, 33, 30, 26, 21, 15,
etc.


MATHEMATICA

Table[(n^2  n)/2  Prepend[Accumulate@ Range[0, n  3], 0], {n, 12}] // Flatten (* Michael De Vlieger, Apr 12 2016 *)


CROSSREFS

Cf. A000096, A000217, A002260, A002262, A005408, A005563, A049780, A084990, A094728, A120070, A158405, A158894.
Sequence in context: A307967 A131077 A175520 * A072464 A262871 A160745
Adjacent sequences: A271665 A271666 A271667 * A271669 A271670 A271671


KEYWORD

nonn,tabl


AUTHOR

Paul Curtz, Apr 12 2016


STATUS

approved



