

A162610


Triangle read by rows in which row n lists n terms, starting with 2n1, with gaps = n1 between successive terms.


20



1, 3, 4, 5, 7, 9, 7, 10, 13, 16, 9, 13, 17, 21, 25, 11, 16, 21, 26, 31, 36, 13, 19, 25, 31, 37, 43, 49, 15, 22, 29, 36, 43, 50, 57, 64, 17, 25, 33, 41, 49, 57, 65, 73, 81, 19, 28, 37, 46, 55, 64, 73, 82, 91, 100, 21, 31, 41, 51, 61, 71, 81, 91, 101, 111, 121
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

Note that the last term of the nth row is the nth square A000290(n).
Row sums are n*(n^2+2*n1)/2, apparently in A127736.  R. J. Mathar, Jul 20 2009


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..10000


FORMULA

T(n,k) = n+k*nk, 1<=k<=n.  R. J. Mathar, Oct 20 2009
T(n,k) = (k+1)*(n1)+1.  Reinhard Zumkeller, Jan 19 2013


EXAMPLE

Triangle begins:
1
3, 4
5, 7, 9
7, 10, 13, 16
9, 13, 17, 21, 25
11, 16, 21, 26, 31, 36


MATHEMATICA

Flatten[Table[NestList[#+n1&, 2n1, n1], {n, 15}]] (* Harvey P. Dale, Oct 20 2011 *)


PROG

(Python) # From R. J. Mathar, Oct 20 2009
def A162610(n, k):
return 2*n1+(k1)*(n1)
print([A162610(n, k) for n in range(1, 20) for k in range(1, n+1)])
(Haskell)
a162610 n k = k * n  k + n
a162610_row n = map (a162610 n) [1..n]
a162610_tabl = map a162610_row [1..]
 Reinhard Zumkeller, Jan 19 2013


CROSSREFS

Cf. A000027, A000290, A159797, A159798.
Cf. A209297; A005408 (left edge), A000290 (right edge), A127736 (row sums), A056220 (central terms), A026741 (number of odd terms per row), A142150 (number of even terms per row), A221491 (number of primes per row).
Sequence in context: A174269 A112882 A180152 * A155935 A081606 A079945
Adjacent sequences: A162607 A162608 A162609 * A162611 A162612 A162613


KEYWORD

easy,tabl,nonn


AUTHOR

Omar E. Pol, Jul 09 2009


EXTENSIONS

More terms from R. J. Mathar, Oct 20 2009


STATUS

approved



