A222405 -id:A222405 - cp's OEIS frontend

A222403 Triangle read by rows: left and right edges are A000217, interior entries are filled in using the Pascal triangle rule.

0, 1, 1, 3, 2, 3, 6, 5, 5, 6, 10, 11, 10, 11, 10, 15, 21, 21, 21, 21, 15, 21, 36, 42, 42, 42, 36, 21, 28, 57, 78, 84, 84, 78, 57, 28, 36, 85, 135, 162, 168, 162, 135, 85, 36, 45, 121, 220, 297, 330, 330, 297, 220, 121, 45, 55, 166, 341, 517, 627, 660, 627, 517, 341, 166, 55

Offset: 0

N. J. A. Sloane, Feb 18 2013

In general, if the sequence defining the left and right edges is [a_0, a_1, ...], the row sums [s_0, s_1, ...] are given by s_0=a_0 and, for n>0,
s_n = 2a_n + Sum_{i=1..n-1} 2^(n-i) a_i.
Conversely, given the rows sums [s_0, s_1, ...], the edge sequence is [a_0, a_1, ...] where a_0=s_0 and, for n>0, a_n = (s_n - Sum_{i=1..n-1} s_i)/2.

			Triangle begins:
0
1, 1
3, 2, 3
6, 5, 5, 6
10, 11, 10, 11, 10
15, 21, 21, 21, 21, 15
21, 36, 42, 42, 42, 36, 21
28, 57, 78, 84, 84, 78, 57, 28
...

Robert Israel, Table of n, a(n) for n = 0..10010

Other triangles of this type: A007318, A051666, A134634, A222404, A222405.
Cf. A000217.
Row sums are A005803.

d:=[seq(n*(n+1)/2,n=0..14)];
f:=proc(d) local T,M,n,i;
M:=nops(d);
T:=Array(0..M-1,0..M-1);
for n from 0 to M-1 do T[n,0]:=d[n+1]; T[n,n]:=d[n+1]; od:
for n from 2 to M-1 do
for i from 1 to n-1 do T[n,i]:=T[n-1,i-1]+T[n-1,i]; od: od:
lprint("triangle:");
for n from 0 to M-1 do lprint(seq(T[n,i],i=0..n)); od:
lprint("row sums:");
lprint([seq( add(T[i,j],j=0..i), i=0..M-1)]);
end;
f(d);

t[n_, n_] := n*(n+1)/2; t[n_, 0] := n*(n+1)/2; t[n_, k_] := t[n, k] = t[n-1, k-1] + t[n-1, k]; Table[t[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 20 2014 *)

G.f. as triangle: (1+x-4*x*y+x*y^2+x^2*y^2)*y/((1-y)^2*(-x*y+1)^2*(-x*y-y+1)). - Robert Israel, Apr 04 2018

A222404 Triangle read by rows: left and right edges are A002378, interior entries are filled in using the Pascal triangle rule.

Original entry on oeis.org

0, 2, 2, 6, 4, 6, 12, 10, 10, 12, 20, 22, 20, 22, 20, 30, 42, 42, 42, 42, 30, 42, 72, 84, 84, 84, 72, 42, 56, 114, 156, 168, 168, 156, 114, 56, 72, 170, 270, 324, 336, 324, 270, 170, 72, 90, 242, 440, 594, 660, 660, 594, 440, 242, 90, 110, 332, 682, 1034, 1254, 1320, 1254, 1034, 682, 332, 110

Offset: 0

N. J. A. Sloane, Feb 18 2013

			Triangle begins:
0
2, 2
6, 4, 6
12, 10, 10, 12
20, 22, 20, 22, 20
30, 42, 42, 42, 42, 30
42, 72, 84, 84, 84, 72, 42
56, 114, 156, 168, 168, 156, 114, 56
...

Cf. A007318, A002378, A222403, A222405.

Row sums are 4*A000295.

d:=[seq(n*(n+1),n=0..14)];
f:=proc(d) local T,M,n,i;
M:=nops(d);
T:=Array(0..M-1,0..M-1);
for n from 0 to M-1 do T[n,0]:=d[n+1]; T[n,n]:=d[n+1]; od:
for n from 2 to M-1 do
for i from 1 to n-1 do T[n,i]:=T[n-1,i-1]+T[n-1,i]; od: od:
lprint("triangle:");
for n from 0 to M-1 do lprint(seq(T[n,i],i=0..n)); od:
lprint("row sums:");
lprint([seq( add(T[i,j],j=0..i), i=0..M-1)]);
end;
f(d);

t[n_, n_] := n*(n+1); t[n_, 0] := n*(n+1); t[n_, k_] := t[n, k] = t[n-1, k-1] + t[n-1, k]; Table[t[n, k], {n, 0, 10}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 20 2014 *)

A027178 a(n) = T(n,0) + T(n,1) + ... + T(n,n), T given by A027170.

Original entry on oeis.org

1, 6, 20, 52, 120, 260, 544, 1116, 2264, 4564, 9168, 18380, 36808, 73668, 147392, 294844, 589752, 1179572, 2359216, 4718508, 9437096, 18874276, 37748640, 75497372, 150994840, 301989780, 603979664, 1207959436, 2415918984

Offset: 0

Clark Kimberling

nonn

Define a triangle U(n,k) with U(n,0) = n*(n+1) + 1 for n>=0 and U(r,c) = U(r-1,c-1) + U(r-1,c). The sum of the terms in row n is a(n). The first rows are 1; 3, 3; 7, 6, 7; 13, 13, 13, 13; 21, 26, 26, 26, 21; row sums are 1, 6, 20, 52, 120. - J. M. Bergot, Feb 15 2013

This triangle is now A222405. - N. J. A. Sloane, Feb 18 2013

Cf. A222405.

a(n) = 9*2^n - 4n - 8 (conjectured). - Ralf Stephan, Feb 13 2004
Conjectures from Colin Barker, Feb 17 2016: (Start)
a(n) = 4*a(n-1)-5*a(n-2)+2*a(n-3) for n>2.
G.f.: (1+x)^2 / ((1-x)^2*(1-2*x)).
(End)

A134634 Triangle formed by Pascal's rule with borders = A000108.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 5, 4, 4, 5, 14, 9, 8, 9, 14, 42, 23, 17, 17, 23, 42, 132, 65, 40, 34, 40, 65, 132, 429, 197, 105, 74, 74, 105, 197, 429, 1430, 626, 302, 179, 148, 179, 302, 626, 1430, 4862, 2056, 928, 481, 327, 327, 481, 928, 2056, 4862, 16796, 6918, 2984, 1409, 808, 654, 808, 1409, 2984, 6918, 16796, 58786, 23714, 9902, 4393, 2217, 1462, 1462, 2217, 4393, 9902, 23714, 58786

Offset: 0

Gary W. Adamson, Nov 04 2007

Row sums = A134635: (1, 2, 6, 18, 54, 164, ...).

			First few rows of the triangle:
    1;
    1,  1;
    2,  2,  2;
    5,  4,  4,  5;
   14,  9,  8,  9, 14;
   42, 23, 17, 17, 23, 42;
  132, 65, 40, 34, 40, 65, 132;
  ...

Cf. A000108, A134635, A222403, A222404, A222405.

Triangle, given right and left borders consist of the Catalan sequence, A000108; then T(n,k) = T(n-1,k) + T(n-1,k-1).

Recomputed by N. J. A. Sloane, Feb 18 2013

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A222403 Triangle read by rows: left and right edges are A000217, interior entries are filled in using the Pascal triangle rule.

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A222404 Triangle read by rows: left and right edges are A002378, interior entries are filled in using the Pascal triangle rule.

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A027178 a(n) = T(n,0) + T(n,1) + ... + T(n,n), T given by A027170.

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A134634 Triangle formed by Pascal's rule with borders = A000108.

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