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A014421
Odd elements in Pascal's triangle.
7
1, 1, 1, 1, 1, 1, 3, 3, 1, 1, 1, 1, 5, 5, 1, 1, 15, 15, 1, 1, 7, 21, 35, 35, 21, 7, 1, 1, 1, 1, 9, 9, 1, 1, 45, 45, 1, 1, 11, 55, 165, 165, 55, 11, 1, 1, 495, 495, 1, 1, 13, 715, 1287, 1287, 715, 13, 1, 1, 91, 1001, 3003, 3003, 1001, 91, 1, 1, 15, 105, 455, 1365, 3003, 5005
OFFSET
0,7
COMMENTS
The number of terms of the n-row is A001316(n). - Michel Marcus, Jan 11 2016
LINKS
Robert Israel, Table of n, a(n) for n = 0..10070 (rows 0 to 375, flattened)
Arvind Ayyer, Amritanshu Prasad, Steven Spallone, Odd partitions in Young's lattice, arXiv:1601.01776 [math.CO], 2016. See Fig. 3.
A. M. Reiter, Determining the dimension of fractals generated by Pascal’s triangle, Fibonacci Quart, 31(2):112-120, 1993.
EXAMPLE
Triangle starts:
1;
1, 1;
1, 1;
1, 3, 3, 1;
1, 1;
1, 5, 5, 1;
1, 15, 15, 1;
1, 7, 21, 35, 35, 21, 7, 1;
...
MAPLE
select(type, [seq(seq(binomial(n, k), k=0..n), n=0..20)], odd); # Robert Israel, Jan 11 2016
MATHEMATICA
Select[ Flatten[ Table[ Binomial[ n, i ], {n, 0, 20}, {i, 0, n} ] ], OddQ ]
PROG
(PARI) tabf(nn) = {for (n=0, nn, for (k=0, n, b = binomial(n, k); if (b % 2, print1(b, ", "))); print(); ); } \\ Michel Marcus, Jan 11 2016
CROSSREFS
Cf. A143333. [From Reinhard Zumkeller, Oct 24 2010]
Sequence in context: A016554 A046533 A046532 * A127197 A114231 A079075
KEYWORD
nonn,easy,tabf
EXTENSIONS
More terms from Erich Friedman
Keyword tabl replaced by tabf by Reinhard Zumkeller, Oct 21 2010
Offset changed to 0 by Michel Marcus, Jan 11 2016
STATUS
approved