cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A253768 Partial sums of A098550.

Original entry on oeis.org

1, 3, 6, 10, 19, 27, 42, 56, 61, 67, 92, 104, 139, 155, 162, 172, 193, 213, 240, 262, 301, 312, 325, 358, 384, 429, 457, 508, 540, 557, 575, 660, 684, 739, 773, 838, 874, 965, 995, 1044, 1082, 1145, 1164, 1206, 1301, 1345, 1402, 1442, 1511, 1561, 1584, 1632, 1747, 1799, 1874, 1920, 2001, 2057, 2144, 2206
Offset: 1

Views

Author

Omar E. Pol, Jan 27 2015

Keywords

Comments

For the partial sums of EKG sequence see A065057.

Crossrefs

Programs

  • Mathematica
    f[lst_] := Block[{k = 4}, While[GCD[lst[[-2]], k] == 1 || GCD[lst[[-1]], k] > 1 || MemberQ[lst, k], k++]; Append[lst, k]];
    Nest[f, {1, 2, 3}, 68] // Accumulate (* Jean-François Alcover, Oct 04 2018, after Robert G. Wilson v *)

A065078 Triangle read by rows: a(n,m) = T[n,m,m] where T[i,j,k] is the 3-dimensional pyramid defined by T[n,m,0]=1 and T[i,j,k]=0 if j>i or k>j and T[i,j,k]=T[i-1,j,k]+T[i,j-1,k]+T[i,j,k-1].

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 1, 3, 10, 18, 1, 4, 22, 79, 162, 1, 5, 40, 220, 831, 1851, 1, 6, 65, 492, 2681, 10488, 24661, 1, 7, 98, 962, 6883, 37367, 149743, 365613, 1, 8, 140, 1715, 15318, 105731, 573051, 2336243, 5863881, 1, 9, 192, 2856, 30840, 258604, 1742770
Offset: 0

Views

Author

Wouter Meeussen, Nov 09 2001

Keywords

Comments

Number of paths to T[n,m,m] counted from the bottom plane (or T[n,m,0]).

Examples

			[3,2,2] can be reached from 3*[1,1,0] + 3*[2,1,0] + 2*[2,2,0] + 1*[3,1,0] + 1*[3,2,0], so a(3,2) = 3 + 3 + 2 + 1 + 1 =10.
Triangle begins
1;
1, 1;
1, 2, 3;
1, 3, 10, 18;
1, 4, 22, 79, 162;
		

Crossrefs

Last number in each row is A065058.

Formula

T[0, 0, 0] := 1; T[x_, y_, z_] := 0 /; (x< y || y< z); T[u_, v_, 0] := 1; T[, 0, 0] := 1; T[x, y_, z_] := (T[x, y, z]= T[x-1, y, z]+T[x, y-1, z] +T[x, y, z-1]) /; (y<=x ||z<=y); Table[T[x, y, y], {x, 0, 10}, {y, 0, x}]

A256528 Partial sums of A254077.

Original entry on oeis.org

1, 3, 6, 10, 16, 24, 33, 43, 55, 60, 74, 89, 96, 114, 135, 151, 178, 198, 231, 255, 266, 292, 314, 327, 355, 394, 426, 456, 500, 525, 559, 594, 611, 651, 702, 738, 806, 848, 900, 945, 983, 1031, 1050, 1096, 1153, 1176, 1230, 1299, 1349, 1412, 1467, 1516, 1576, 1632, 1697, 1755, 1825, 1854, 1916, 2003, 2034, 2100, 2193, 2257
Offset: 1

Views

Author

Omar E. Pol, May 08 2015

Keywords

Comments

First differs from A256529 at a(29).

Crossrefs

A256529 Partial sums of A255582.

Original entry on oeis.org

1, 3, 6, 10, 16, 24, 33, 43, 55, 60, 74, 89, 96, 114, 135, 151, 178, 198, 231, 255, 266, 292, 314, 327, 355, 394, 426, 456, 490, 515, 532, 567, 618, 658, 700, 738, 774, 793, 837, 894, 940, 985, 1008, 1056, 1125, 1175, 1229, 1281, 1339, 1395, 1424, 1473, 1560, 1623, 1683, 1760, 1822, 1877, 1908, 1973, 2066, 2136, 2202, 2266
Offset: 1

Views

Author

Omar E. Pol, May 08 2015

Keywords

Comments

First differs from A256528 at a(29).

Crossrefs

Showing 1-4 of 4 results.