Original entry on oeis.org
1, 2, 1, 3, 2, 3, 4, 3, 6, 5, 5, 4, 9, 10, 7, 6, 5, 12, 15, 14, 9, 7, 6, 15, 20, 21, 18, 11, 8, 7, 18, 25, 28, 27, 22, 13, 9, 8, 21, 30, 35, 36, 33, 26, 15, 10, 9, 24, 35, 42, 45, 44, 39, 30, 17, 11, 10, 27, 40, 49, 54, 55, 52, 45, 34, 19
Offset: 1
First few rows of the triangle:
1;
2, 1;
3, 2, 3;
4, 3, 6, 5;
5, 4, 9, 10, 7;
6, 5, 12, 15, 14, 9;
7, 6, 15, 20, 21, 18, 11;
8, 7, 18, 25, 28, 27, 22, 13;
9, 8, 21, 30, 35, 36, 33, 26, 15;
10, 9, 24, 35, 42, 45, 44, 39, 30, 17;
...
A144693
Triangle read by rows, A000012 * (3*A144328 - 2*A000012), where A000012 means a lower triangular matrix of all 1's.
Original entry on oeis.org
1, 2, 1, 3, 2, 4, 4, 3, 8, 7, 5, 4, 12, 14, 10, 6, 5, 16, 21, 20, 13, 7, 6, 20, 28, 30, 26, 16, 8, 7, 24, 35, 40, 39, 32, 19, 9, 8, 28, 42, 50, 52, 48, 38, 22, 10, 9, 32, 49, 60, 65, 64, 57, 44, 25, 11, 10, 36, 56, 70, 78, 80, 76, 66, 50, 28
Offset: 1
Partial sums by columns of the triangle (3*A144328 - 2*A000012):
1;
1, 1;
1, 1, 4;
1, 1, 4, 7;
1, 1, 4, 7, 10;
...
First few rows of the triangle:
1;
2, 1
3, 2, 4;
4, 3, 8, 7;
5, 4, 12, 14, 10;
6, 5, 16, 21, 20, 13;
7, 6, 20, 28, 30, 26, 16;
8, 7, 24, 35, 40, 39, 32, 19;
...
-
A144693:= func< n,k | k eq 1 select n else (3*k-5)*(n-k+1) >;
[A144693(n,k): k in [1..n], n in [1..12]]; // G. C. Greubel, Oct 19 2021
-
T[n_, k_]:= (3*k -5 +3*Boole[k==1])*(n-k+1);
Table[T[n, k], {n,12}, {k,n}]//Flatten (* G. C. Greubel, Oct 19 2021 *)
-
def A144693(n,k): return (3*k -5 +3*bool(k==1))*(n-k+1)
flatten([[A144693(n,k) for k in (1..n)] for n in (1..12)]) # G. C. Greubel, Oct 19 2021
Original entry on oeis.org
1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 4, 3, 4, 1, 1, 4, 8, 4, 5, 1, 1, 9, 8, 13, 5, 6, 1, 1, 9, 22, 13, 19, 6, 7, 1, 1, 23, 22, 41, 19, 26, 7, 8, 1, 1, 23, 64, 41, 67, 26, 34, 8, 9, 1, 1, 65, 64, 131, 67, 101, 34, 43, 9, 10, 1, 1
Offset: 0
A053121 starts:
1;
0, 1;
1, 0, 1;
0, 2, 0, 1;
...
Taking partial sums from the top, we get A145972:
1;
1, 1;
2, 1, 1;
2, 3, 1, 1;
4, 3, 4, 1, 1;
4, 8, 4, 5, 1, 1;
9, 8, 13, 5, 6, 1, 1;
9, 22, 13, 19, 6, 7, 1, 1;
23, 22, 41, 19, 26, 7, 8, 1, 1;
23, 64, 41, 67, 26, 34, 8, 9, 1, 1;
...
Original entry on oeis.org
1, 1, 2, 1, 4, 3, 8, 7, 1, 16, 15, 5, 32, 31, 16, 1, 64, 63, 42, 7, 128, 127, 99, 29, 1256, 255, 219, 93, 9, 512, 511, 466, 256, 46, 1, 1024, 1023, 968, 638, 176, 11, 2048, 2047, 1981, 1486, 562, 67, 1
Offset: 0
First few rows of the triangle =
1;
1;
2, 1;
4, 3;
8, 7, 1;
16, 15, 5;
32, 31, 16, 1;
64, 63, 42, 7;
128, 127, 99, 29, 1;
256, 255, 219, 93, 9;
512, 511, 466, 256, 46, 1;
1024, 1023, 968, 638, 176, 11;
2048, 2047, 1981, 1486, 562, 67, 1;
...
Original entry on oeis.org
1, 2, 0, 4, 1, 0, 7, 4, 1, 0, 12, 11, 5, 1, 0, 20, 26, 17, 6, 1, 0, 33, 56, 48, 24, 7, 1, 0, 54, 114, 121, 78, 32, 8, 1, 0, 88, 223, 283, 223, 117, 41, 9, 1, 0, 143, 424, 627, 584, 372, 166, 51, 10, 1, 0, 232, 789, 1334, 1434, 1073, 579, 226, 62, 11, 1, 0, 376, 1444, 2750, 3352, 2879, 1818, 856, 298, 74, 12, 1, 0
Offset: 1
First few rows of the triangle =
1;
2, 0;
4, 1, 0;
7, 4, 1, 0;
12, 11, 5, 1, 0;
20, 26, 17, 6, 1, 0;
33, 56, 48, 24, 7, 1, 0;
54, 114, 121, 78, 32, 8, 1, 0;
88, 223, 283, 223, 117, 41, 9, 1, 0;
143, 424, 627, 584, 372, 166, 51, 10, 1, 0;
232, 789, 1334, 1434, 1073, 579, 226, 62, 11, 1, 0;
...
a(21) = 0 inserted and more terms from
Georg Fischer, May 29 2023
Original entry on oeis.org
1, 3, 0, 7, 1, 0, 14, 5, 1, 0, 26, 16, 6, 1, 0, 46, 42, 23, 7, 1, 0, 79, 98, 71, 31, 8, 1, 0, 133, 212, 192, 109, 40, 9, 1, 0, 221, 435, 475, 332, 157, 50, 10, 1, 0, 364, 859, 1102, 916, 529, 216, 61, 11, 1, 0, 596, 1648, 2436, 2350, 1602, 795, 287, 73, 12, 1, 0, 972, 3092, 5186, 5702, 4481, 2613, 1143, 371, 86, 13, 1, 0
Offset: 0
First few rows of the triangle:
1;
3, 0;
7, 1, 0;
14, 5, 1, 0;
26, 16, 6, 1, 0;
46, 42, 23, 7, 1, 0
79, 98, 71, 31, 8, 1, 0;
133, 212, 192, 109, 40, 9, 1, 0;
221, 435, 475, 332, 157, 50, 10, 1, 0;
364, 859, 1102, 916, 529, 216, 61, 11, 1, 0;
596, 1648, 2436, 2350, 1602, 795, 287, 73, 12, 1, 0;
...
a(44) = 0 corrected and more terms from
Georg Fischer, Jun 05 2023
Original entry on oeis.org
1, 1, 1, 2, 2, 2, 2, 4, 4, 4, 3, 6, 10, 8, 8, 3, 9, 16, 24, 16, 16, 4, 12, 28, 40, 56, 32, 32, 4, 16, 40, 80, 96, 128, 64, 64, 5, 20, 60, 120, 216, 224, 288, 128, 128, 5, 25, 80, 200, 336, 560, 512, 640, 256, 256, 6, 30, 110, 280, 616, 896, 1408, 1152, 1408, 512, 512
Offset: 0
First few rows of the triangle, n>=0:
1;
1, 1;
2, 2, 2;
2, 4, 4, 4;
3, 6, 10, 8, 8;
3, 9, 16, 24, 16, 16;
4, 12, 28, 40, 56, 32, 32;
4, 16, 40, 80, 96, 128, 64, 64;
5, 20, 60, 120, 216, 224, 288, 128, 128;
5, 25, 80, 200, 336, 560, 512, 640, 256, 256;
-
A011782:= func< n | n eq 0 select 1 else 2^(n-1) >;
function t(n, k) // t = A059576
if k eq 0 or k eq n then return A011782(n);
else return 2*t(n-1, k-1) + 2*t(n-1, k) - (2 - 0^(n-2))*t(n-2, k-1);
end if; return t;
end function;
A157898:= func< n, k | (&+[(-1)^(n-j)*Binomial(n, j)*t(j, k): j in [k..n]]) >;
A157071:= func< n,k | (&+[A157898(j+k,k): j in [0..n-k]]) >;
[A157071(n, k): k in [0..n], n in [0..12]]; // G. C. Greubel, Aug 27 2025
-
t[n_, k_]:= t[n,k]= If[k==0 || k==n, 2^(n-1) +Boole[n==0]/2, 2*t[n-1,k-1] +2*t[n-1,k] - (2 -Boole[n==2])*t[n-2,k-1]]; (* t = A059576 *)
A157898[n_, k_]:= A157898[n,k]= Sum[(-1)^(n-j)*Binomial[n,j]*t[j,k], {j,k,n}];
A157901[n_, k_]:= A157901[n,k]= Sum[A157898[j+k,k], {j,0,n-k}];
Table[A157901[n,k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Aug 27 2025 *)
-
@CachedFunction
def t(n, k): # t = A059576
if (k==0 or k==n): return bool(n==0)/2 + 2^(n-1) # A011782
else: return 2*t(n-1, k-1) + 2*t(n-1, k) - (2 - 0^(n-2))*t(n-2, k-1)
def A157898(n, k): return sum((-1)^(n+k-j)*binomial(n, j+k)*t(j+k, k) for j in range(n-k+1))
def A157071(n,k): return sum(A157898(j+k,k) for j in range(n-k+1))
print(flatten([[A157071(n,k) for k in range(n+1)] for n in range(10)])) # G. C. Greubel, Aug 27 2025
Edited by the Associate Editors of the OEIS, Apr 10 2009
Original entry on oeis.org
1, 3, 1, 6, 3, 2, 10, 6, 5, 3, 15, 10, 9, 7, 4, 21, 15, 14, 12, 9, 5, 28, 21, 20, 18, 15, 11, 6, 36, 28, 27, 25, 22, 18, 13, 7, 45, 36, 35, 33, 30, 26, 21, 15, 8, 55, 45, 44, 42, 39, 35, 30, 24, 17, 9, 66, 55, 54, 52, 49, 45, 40, 34, 27, 19, 10
Offset: 0
First few rows of the triangle =
1;
3, 1;
6, 3, 2;
10, 6, 5, 3;
15, 10, 9, 7, 4;
21, 15, 14, 12, 9, 5;
28, 21, 10, 18, 15, 11, 6;
36, 28, 27, 25, 22, 18, 13, 7;
45, 36, 35, 33, 30, 26, 21, 15, 8;
55, 45, 44, 42, 39, 35, 30, 24, 17, 9;
66, 55, 54, 52, 49, 45, 40, 34, 27, 19, 10;
78, 66, 65, 63, 60, 56, 51, 45, 38, 30, 21, 11;
91, 78, 77, 75, 72, 68, 63, 57, 50, 42, 33, 23, 12;
...
-
T[n_, k_]:= If[k==0, Binomial[n+2, 2], (n+1-k)*(n+k)/2];
Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Dec 26 2021 *)
-
def A158822(n,k):
if (k==0): return binomial(n+2, 2)
else: return (n-k+1)*(n+k)/2
flatten([[A158822(n,k) for k in (0..n)] for n in (0..15)]) # G. C. Greubel, Dec 26 2021
Original entry on oeis.org
1, 1, 1, 2, 1, 2, 2, 2, 1, 3, 3, 2, 3, 1, 4, 3, 3, 2, 4, 1, 5, 4, 3, 4, 2, 5, 1, 6, 4, 4, 3, 5, 2, 6, 1, 7, 5, 4, 5, 3, 6, 2, 7, 1, 8, 5, 5, 4, 6, 3, 7, 2, 8, 1, 9, 6, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10, 6, 6, 5, 7, 4, 8, 3, 9, 2, 10, 1, 11
Offset: 1
First few rows of the triangle =
1;
1, 1;
2, 1, 2;
2, 2, 1, 3;
3, 2, 3, 1, 4;
3, 3, 2, 4, 1, 5;
4, 3, 4, 2, 5, 1, 6;
4, 4, 3, 5, 2, 6, 1, 7;
5, 4, 5, 3, 6, 2, 7, 1, 8;
5, 5, 4, 6, 3, 7, 2, 8, 1, 9;
6, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10;
6, 6, 5, 7, 4, 8, 3, 9, 2, 10, 1, 11;
7, 6, 7, 5, 8, 4, 9, 3, 10, 2, 11, 1, 12;
7, 7, 6, 8, 5, 9, 4, 10, 3, 11, 2, 12, 1, 13;
...
Original entry on oeis.org
1, 2, 1, 3, 1, 1, 4, 2, 2, 1, 5, 2, 2, 1, 1, 6, 3, 2, 1, 2, 1, 7, 3, 3, 1, 3, 1, 1, 8, 4, 4, 2, 4, 2, 2, 1, 9, 4, 4, 2, 4, 2, 2, 1, 1, 10, 5, 4, 2, 4, 2, 2, 1, 2, 1, 11, 5, 5, 2, 4, 2, 2, 1, 3, 1, 1, 12, 6, 6, 3, 4, 2, 2, 1, 4, 2, 2, 1
Offset: 0
First few rows of the triangle =
1;
2, 1;
3, 1, 1;
4, 2, 2, 1;
5, 2, 2, 1, 1;
6, 3, 2, 1, 2, 1;
7, 3, 3, 1, 3, 1, 1;
8, 4, 4, 2, 4, 2, 2, 1;
9, 4, 4, 2, 4, 2, 2, 1, 1;
10, 5, 4, 2, 4, 2, 2, 1, 2, 1;
11, 5, 5, 2, 4, 2, 2, 1, 3, 1, 1;
12, 6, 6, 3, 4, 2, 2, 1, 4, 2, 2, 1;
13, 6, 6, 3, 5, 2, 2, 1, 5, 2, 2, 1, 1;
...
-
A166556:= func< n,k | (&+[(Binomial(j,k) mod 2): j in [k..n]]) >;
[A166556(n,k): k in [0..n], n in [0..15]]; // G. C. Greubel, Dec 02 2024
-
A166556 := proc(n,k)
local j;
add(A047999(j,k),j=k..n) ;
end proc: # R. J. Mathar, Jul 21 2016
-
A166556[n_, k_]:= Sum[Mod[Binomial[j,k], 2], {j,k,n}];
Table[A166556[n,k], {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Dec 02 2024 *)
-
def A166556(n,k): return sum(binomial(j,k)%2 for j in range(k,n+1))
print(flatten([[A166556(n,k) for k in range(n+1)] for n in range(13)])) # G. C. Greubel, Dec 02 2024
Comments