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 1-5 of 5 results.

A322610 Numbers that are sums (of a nonempty sequence) of consecutive centered triangular numbers.

Original entry on oeis.org

1, 4, 5, 10, 14, 15, 19, 29, 31, 33, 34, 46, 50, 60, 64, 65, 77, 85, 96, 106, 109, 110, 111, 136, 141, 149, 160, 166, 170, 174, 175, 194, 195, 199, 226, 235, 245, 255, 258, 259, 260, 274, 302, 304, 316, 330, 335, 354, 361, 364, 365, 368, 369, 394, 409, 411, 434, 440, 460, 471, 490, 496, 500
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 20 2018

Keywords

Links

Crossrefs

Cf. A005448, A005918 (2 consec), A006003, A034706, A320728, A322468, A322611, A322638, A322640.

Programs

  • Mathematica
    anmax = 1000; nmax = Floor[Sqrt[2*anmax/3]] + 1; Select[Union[Flatten[Table[Sum[(3*k^2 + 3*k + 2)/2, {k, i, j}], {i, 0, nmax}, {j, i, nmax}]]], # <= anmax &] (* Vaclav Kotesovec, Dec 21 2018 *)

A322611 Numbers that are sums (of a nonempty sequence) of consecutive centered square numbers.

Original entry on oeis.org

1, 5, 6, 13, 18, 19, 25, 38, 41, 43, 44, 61, 66, 79, 84, 85, 102, 113, 127, 140, 145, 146, 181, 187, 198, 212, 221, 225, 230, 231, 258, 259, 265, 300, 313, 325, 326, 338, 343, 344, 365, 402, 404, 421, 439, 445, 470, 481, 483, 486, 488, 489, 524, 545, 547, 578, 585, 613, 626, 651, 660
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 20 2018

Keywords

Links

Crossrefs

Cf. A001844, A005900, A034705, A320728, A322479, A322610, A322638, A322640.

Programs

  • Mathematica
    anmax = 1000; nmax = Floor[Sqrt[anmax/2]] + 1; Select[Union[Flatten[Table[Sum[k^2 + (k + 1)^2, {k, i, j}], {i, 0, nmax}, {j, i, nmax}]]], # <= anmax &] (* Vaclav Kotesovec, Dec 21 2018 *)

A322640 Numbers that are sums of consecutive centered heptagonal numbers (A069099).

Original entry on oeis.org

0, 1, 8, 9, 22, 30, 31, 43, 65, 71, 73, 74, 106, 114, 136, 144, 145, 148, 177, 197, 220, 242, 250, 251, 253, 254, 316, 325, 345, 368, 386, 390, 398, 399, 450, 451, 463, 522, 547, 565, 569, 587, 595, 596, 598, 638, 702, 704, 736, 766, 775, 818, 840, 841, 848, 849, 914, 953
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 21 2018

Keywords

Links

Crossrefs

Cf. A004126, A069099, A152043, A322610, A322611, A322636, A322638, A320728.

Programs

  • Mathematica
    terms = 58;
nmax = 17; kmax =  8; (* empirical *)
T = Table[(7 n^2 - 7 n + 2)/2, {n, 1, nmax}];
Union[{0}, T, Table[k MovingAverage[T, k], {k, 2, kmax}] // Flatten][[1 ;; terms]] (* Jean-François Alcover, Dec 27 2018 *)

A322653 Numbers that are sums of consecutive octagonal pyramidal numbers (A002414).

Original entry on oeis.org

0, 1, 9, 10, 30, 39, 40, 70, 100, 109, 110, 135, 205, 231, 235, 244, 245, 364, 366, 436, 466, 475, 476, 540, 595, 730, 765, 800, 830, 839, 840, 904, 1045, 1135, 1270, 1305, 1340, 1370, 1379, 1380, 1386, 1669, 1794, 1810, 1900, 2035, 2105, 2135, 2144, 2145, 2275, 2350, 2431, 2714
Offset: 1

Views

Author

Ilya Gutkovskiy, Dec 21 2018

Keywords

Links

Crossrefs

Cf. A002414, A002419, A320728, A321450, A322468, A322479, A322637, A322651, A322652.

A338447 Sums of consecutive odd positive cubes.

Original entry on oeis.org

1, 27, 28, 125, 152, 153, 343, 468, 495, 496, 729, 1072, 1197, 1224, 1225, 1331, 2060, 2197, 2403, 2528, 2555, 2556, 3375, 3528, 4257, 4600, 4725, 4752, 4753, 4913, 5572, 6859, 6903, 7632, 7975, 8100, 8127, 8128, 8288, 9261, 10485, 11772, 11816, 12167, 12545, 12888, 13013
Offset: 1

Views

Author

Ilya Gutkovskiy, Oct 28 2020

Keywords

Examples

			495 is in the sequence because 495 = 3^3 + 5^3 + 7^3.

Links

Crossrefs

Cf. A002593, A016755, A042965, A217843, A265845, A290276, A320728.

Programs

  • PARI
    lista(nn) = {my(list = List()); forstep (i=1, nn, 2, my(s = 0); forstep(j=i, 1, -2, s += j^3; if (s > nn^3, break); listput(list, s););); Set(list);} \\ Michel Marcus, Nov 13 2020
Showing 1-5 of 5 results.

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