login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A334460 Irregular triangle read by rows: T(n,k) is the number of partitions of n into k consecutive parts that differ by 4, and the first element of column k is in the row that is the k-th hexagonal number (A000384). 10
1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET
1
COMMENTS
T(n,k) is 0 or 1, so T(n,k) represents the "existence" of the mentioned partition: 1 = exists, 0 = does not exist.
Since the trivial partition n is counted, so T(n,1) = 1.
This is an irregular triangle read by rows: T(n,k), n >= 1, k >= 1, in which column k lists 1's interleaved with k-1 zeros, and the first element of column k is in the row that is the k-th hexagonal number.
This triangle can be represented with a diagram of overlapping curves, in which every column of triangle is represented by a periodic curve.
For a general theorem about the triangles of this family see A303300.
LINKS
EXAMPLE
Triangle begins (rows 1..28):
1;
1;
1;
1;
1;
1, 1;
1, 0;
1, 1;
1, 0;
1, 1;
1, 0;
1, 1;
1, 0;
1, 1;
1, 0, 1;
1, 1, 0;
1, 0, 0;
1, 1, 1;
1, 0, 0;
1, 1, 0;
1, 0, 1;
1, 1, 0;
1, 0, 0;
1, 1, 1;
1, 0, 0;
1, 1, 0;
1, 0, 1;
1, 1, 0, 1;
...
For n = 28 there are three partitions of 28 into consecutive parts that differ by 4, including 28 as a partition. They are [28], [16, 12] and [13, 9, 5, 1]. The number of parts of these partitions are 1, 2, 4 respectively. There are no partitions of this kind with three parts, so the 28th row of the triangle is [1, 1, 0, 1].
MAPLE
A334460 := proc(n, k)
local first1 ;
first1 := A000384(k) ;
if n < first1 then
0 ;
elif modp(n-first1, k) = 0 then
1;
else
0;
end if;
end proc:
for n from 1 to 40 do
for k from 1 do
if n>= A000384(k) then
printf("%d, ", A334460(n, k)) ;
else
break;
end if;
end do:
printf("\n") ;
end do: # R. J. Mathar, Oct 02 2020
CROSSREFS
Row sums give A334461.
Triangles of the same family where the parts differ by d are A051731 (d=0), A237048 (d=1), A303300 (d=2), A330887 (d=3), this sequence (d=4).
Sequence in context: A351824 A365605 A365716 * A071023 A166280 A340371
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, May 01 2020
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 24 14:22 EDT 2024. Contains 374584 sequences. (Running on oeis4.)