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.

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A023563 Convolution of A023531 and A000201.

Original entry on oeis.org

0, 1, 3, 4, 7, 11, 13, 17, 21, 26, 31, 35, 41, 47, 53, 59, 66, 73, 79, 86, 95, 102, 111, 119, 126, 136, 144, 154, 163, 173, 184, 193, 202, 212, 223, 235, 245, 257, 270, 279, 291, 302, 313, 327, 339, 351, 366, 378, 391, 403, 416, 431, 443, 456, 471
Offset: 1

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A023564 Convolution of A023531 and A001950.

Original entry on oeis.org

0, 2, 5, 7, 12, 18, 22, 28, 35, 43, 51, 58, 67, 77, 87, 97, 108, 119, 129, 141, 155, 167, 181, 194, 206, 221, 235, 251, 266, 282, 299, 314, 329, 345, 363, 382, 399, 418, 438, 454, 473, 491, 509, 531, 551, 571, 594, 614, 635, 655, 676, 699, 719
Offset: 1

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A023566 Convolution of A023531 and A014306.

Original entry on oeis.org

0, 0, 1, 1, 0, 2, 2, 1, 2, 3, 2, 2, 3, 2, 4, 4, 3, 3, 4, 4, 4, 5, 3, 4, 5, 5, 5, 5, 5, 5, 6, 6, 5, 6, 6, 5, 7, 6, 5, 7, 7, 7, 6, 6, 8, 7, 7, 7, 8, 8, 8, 8, 7, 6, 9, 9, 7, 9, 9, 8, 8, 9, 7, 8, 9, 10, 10, 9, 8, 10, 10, 10, 9, 9, 9, 10, 10, 10, 11, 10, 11, 10, 11, 10, 10, 10, 11, 9, 11, 10
Offset: 1

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A023858 a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k = floor((n+1)/2), t = A023531.

Original entry on oeis.org

0, 1, 2, 0, 1, 2, 3, 4, 6, 2, 3, 4, 5, 7, 9, 11, 13, 5, 6, 8, 10, 12, 14, 16, 18, 20, 23, 11, 13, 15, 17, 19, 21, 23, 26, 29, 32, 35, 38, 20, 22, 24, 26, 29, 32, 35, 38, 41, 44, 47, 50, 53, 56, 32, 35, 38, 41, 44, 47, 50, 53, 56, 59, 62, 66, 70, 74, 78, 82, 50, 53, 56, 59, 62, 65, 68, 72, 76, 80, 84, 88, 92
Offset: 1

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Programs

  • Mathematica
    Array[Sum[k Boole@ IntegerQ@ Sqrt[8 # + 9] &[# + 1 - k], {k, Floor[(# + 1)/2]}] &, 82] (* Michael De Vlieger, Jun 12 2019 *)

Formula

a(n) = Sum_{k=1..floor((n+1)/2)} A023531(n+1-k). - Sean A. Irvine, Jun 11 2019

Extensions

Missing a(21)=10 inserted and title simplified by Sean A. Irvine, Jun 11 2019

A024307 a(n) = 2*t(n) + 3*t(n-1) + ... + (k+1)*t(n+1-k), where k=floor((n+1)/2) and t = A023531.

Original entry on oeis.org

0, 2, 3, 0, 2, 3, 4, 5, 8, 3, 4, 5, 6, 9, 11, 13, 15, 6, 7, 10, 12, 14, 16, 18, 20, 22, 26, 13, 15, 17, 19, 21, 23, 25, 29, 32, 35, 38, 41, 22, 24, 26, 28, 32, 35, 38, 41, 44, 47, 50, 53, 56, 59, 35, 38, 41, 44, 47, 50, 53, 56, 59, 62, 65, 70, 74, 78, 82, 86, 53, 56, 59, 62, 65, 68, 71, 76, 80, 84
Offset: 1

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Formula

a(n) = Sum_{k=1..floor((n+1)/2)} (k+1) * A023531(n+1-k). - Sean A. Irvine, Jun 26 2019

Extensions

a(64) corrected and title simplified by Sean A. Irvine, Jun 26 2019

A024855 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers), t = A023531.

Original entry on oeis.org

1, 0, 0, 1, 2, 3, 4, 1, 2, 3, 4, 5, 7, 9, 11, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 9, 11, 13, 15, 17, 19, 21, 23, 26, 29, 32, 35, 18, 20, 22, 24, 26, 29, 32, 35, 38, 41, 44, 47, 50, 53, 29, 32, 35, 38, 41, 44, 47, 50, 53, 56, 59, 62, 66, 70, 74, 78, 47, 50, 53, 56, 59, 62, 65, 68, 72, 76, 80
Offset: 2

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Crossrefs

Cf. A023531.

A024870 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (natural numbers >= 2), t = A023531.

Original entry on oeis.org

2, 0, 0, 2, 3, 4, 5, 2, 3, 4, 5, 6, 9, 11, 13, 5, 6, 7, 10, 12, 14, 16, 18, 20, 22, 11, 13, 15, 17, 19, 21, 23, 25, 29, 32, 35, 38, 20, 22, 24, 26, 28, 32, 35, 38, 41, 44, 47, 50, 53, 56, 31, 35, 38, 41, 44, 47, 50, 53, 56, 59, 62, 65, 70, 74, 78, 82, 50, 53, 56, 59, 62, 65, 68, 71, 76, 80, 84, 88
Offset: 2

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Keywords

A024879 a(n) = s(1)s(n) + s(2)s(n-1) + ... + s(k)s(n-k+1), where k = [ n/2 ], s = A023531.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 0, 2, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 2, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 2, 0, 0, 0, 0, 3, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 2, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 0, 2, 0, 1, 0, 0, 2, 1, 0, 1, 1
Offset: 2

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A024882 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023531, t = (Lucas numbers).

Original entry on oeis.org

0, 0, 4, 7, 11, 18, 29, 47, 94, 152, 246, 398, 644, 1042, 1686, 2728, 4537, 7341, 11878, 19219, 31097, 50316, 81413, 131729, 213142, 344871, 559377, 905091, 1464468, 2369559, 3834027, 6203586
Offset: 2

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A024884 a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023531, t = (composite numbers).

Original entry on oeis.org

0, 0, 8, 9, 10, 12, 14, 15, 28, 32, 35, 37, 40, 44, 46, 48, 69, 73, 77, 81, 85, 89, 93, 96, 100, 104, 133, 139, 144, 148, 154, 162, 166, 170, 176, 181, 187, 191, 229, 236, 242, 248, 255, 262, 268, 275, 281, 287, 294, 301, 308, 314, 361, 370, 380, 386, 394, 401, 408, 418, 425
Offset: 2

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Previous Showing 31-40 of 93 results. Next