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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A225360 Partition numbers of the form 9k.

Original entry on oeis.org

135, 297, 792, 1575, 10143, 31185, 63261, 329931, 15796476, 44108109, 4835271870, 7346629512, 12292341831, 18440293320, 107438159466, 129913904637, 156919475295, 250438925115, 1527273599625, 3345365983698, 3646072432125, 7206841706490
Offset: 1

Views

Author

Omar E. Pol, May 05 2013

Keywords

Comments

Intersection of A008591 and A000041.

Examples

			135 is in the sequence because 9*15 = 135 and 135 is a partition number: p(14) = A000041(14) = 135.
		

Crossrefs

Programs

  • Mathematica
    Select[PartitionsP[Range[300]], Mod[#, 9] == 0 &]

Formula

a(n) = 9*A222179(n).

A225361 Partition numbers of the form 11k.

Original entry on oeis.org

11, 22, 77, 176, 231, 297, 385, 627, 792, 1958, 3718, 4565, 6842, 8349, 14883, 21637, 26015, 31185, 44583, 53174, 63261, 173525, 204226, 239943, 281589, 386155, 526823, 715220, 831820, 1121505, 1300156, 1741630, 5392783, 7089500, 8118264, 12132164, 18004327
Offset: 1

Views

Author

Omar E. Pol, May 05 2013

Keywords

Comments

Intersection of A008593 and A000041.

Examples

			22 is in the sequence because 11*2 = 22 and 22 is a partition number: p(8) = A000041(8) = 22.
		

Crossrefs

Programs

  • Mathematica
    Select[PartitionsP[Range[300]], Mod[#, 11] == 0 &]

Formula

a(n) = 11*A225323(n).

A194798 Numbers n having the same parity as the number of partitions of n.

Original entry on oeis.org

1, 2, 3, 5, 7, 8, 10, 13, 17, 22, 23, 26, 28, 29, 30, 33, 34, 35, 37, 39, 40, 41, 42, 43, 46, 49, 50, 51, 53, 58, 61, 62, 63, 64, 66, 67, 69, 70, 71, 73, 74, 77, 78, 80, 81, 83, 84, 85, 86, 87, 89, 91, 93, 94, 95, 96, 98, 99, 100, 105, 106, 107, 108, 110, 111
Offset: 1

Views

Author

Omar E. Pol, Jan 29 2012

Keywords

Comments

Odd positive integers with an odd number of partitions and even positive integers with an even number of partitions. - Omar E. Pol, Mar 17 2012
Union of A067567 and A127219. Note that the union of A163096 and A163097 gives A209920 and the union of A209920 and this sequence gives A001477. - Omar E. Pol, Mar 22 2012

Examples

			10 is in the sequence because the number of partitions of 10 is equal to 42 and both 10 and 42 have the same parity.
		

Crossrefs

Programs

  • Maple
    with(combinat):
    a:= proc(n) option remember; local k;
          for k from 1+`if`(n=1, 0, a(n-1))
          while irem(k+numbpart(k), 2)=1 do od; k
        end:
    seq(a(n), n=1..80); # Alois P. Heinz, Mar 16 2012
  • Mathematica
    Select[Range[200], Mod[PartitionsP[#] - #, 2] == 0 &] (* T. D. Noe, Mar 16 2012 *)

Extensions

More terms from Alois P. Heinz, Mar 16 2012

A087177 Number of even partition numbers <= P(n), where P=A000041.

Original entry on oeis.org

0, 0, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 5, 5, 5, 6, 6, 6, 6, 7, 7, 8, 9, 9, 9, 10, 11, 12, 13, 13, 14, 15, 15, 15, 16, 16, 16, 16, 16, 16, 17, 17, 18, 18, 18, 19, 20, 21, 21, 21, 22, 22, 22, 22, 22, 23, 23, 24, 25, 26, 26, 26, 27, 27, 28, 29, 30, 30, 30, 30, 31, 31, 31, 31, 32, 33, 33
Offset: 0

Views

Author

Reinhard Zumkeller, Aug 23 2003

Keywords

Crossrefs

Programs

  • PARI
    a(n) = sum(k=1, n, !(numbpart(k) % 2)); \\ Michel Marcus, Feb 24 2023

Formula

a(n) = n + 1 - A071754(n).

A087184 Partition numbers of the form 3*k+1.

Original entry on oeis.org

1, 1, 7, 22, 385, 490, 1255, 3010, 3718, 12310, 17977, 21637, 75175, 89134, 204226, 386155, 451276, 831820, 1300156, 1741630, 5392783, 6185689, 10619863, 18004327, 20506255, 34262962, 49995925, 64112359, 104651419, 150198136
Offset: 1

Views

Author

Reinhard Zumkeller, Aug 23 2003

Keywords

Crossrefs

Programs

  • Mathematica
    Select[PartitionsP[Range[0, 100]], Mod[#, 3] == 1 &] (* Amiram Eldar, May 22 2025 *)

Formula

a(n) = A000041(A237276(n)). - Amiram Eldar, May 22 2025

A087185 Partition numbers of the form 3*k+2.

Original entry on oeis.org

2, 5, 11, 56, 77, 101, 176, 1958, 4565, 6842, 26015, 53174, 124754, 173525, 526823, 715220, 966467, 2012558, 2323520, 2679689, 3554345, 7089500, 9289091, 12132164, 13848650, 23338469, 26543660, 30167357, 38887673, 56634173
Offset: 1

Views

Author

Reinhard Zumkeller, Aug 23 2003

Keywords

Crossrefs

Programs

  • Mathematica
    Select[PartitionsP[Range[200]],Divisible[#-2,3]&] (* Harvey P. Dale, Apr 22 2016 *)

Formula

a(n) = A000041(A237277(n)). - Amiram Eldar, May 22 2025

A209920 Numbers n having distinct parity as the number of partitions of n.

Original entry on oeis.org

0, 4, 6, 9, 11, 12, 14, 15, 16, 18, 19, 20, 21, 24, 25, 27, 31, 32, 36, 38, 44, 45, 47, 48, 52, 54, 55, 56, 57, 59, 60, 65, 68, 72, 75, 76, 79, 82, 88, 90, 92, 97, 101, 102, 103, 104, 109, 113, 114, 117, 118, 125, 129, 131, 132, 133, 134, 135, 137, 138, 140
Offset: 1

Views

Author

Omar E. Pol, Mar 16 2012

Keywords

Comments

Odd positive integers with an even number of partitions and nonnegative even integers with an odd number of partitions. Union of A163097 and A163096. Note that the union of A067567 and A127219 gives A194798 and the union of A194798 and this sequence gives A001477.

Examples

			4 is in the sequence because the number of partitions of 4 is equal to 5 and the parity of 4 is distinct to the parity of 5 because 4 is even and 5 is odd.
9 is in the sequence because the number of partitions of 9 is equal to 30 and the parity of 9 is distinct to the parity of 30 because 9 is odd and 30 is even.
		

Crossrefs

A209658 Partition numbers p(n) having the same parity as n.

Original entry on oeis.org

1, 2, 3, 7, 15, 22, 42, 101, 297, 1002, 1255, 2436, 3718, 4565, 5604, 10143, 12310, 14883, 21637, 31185, 37338, 44583, 53174, 63261, 105558, 173525, 204226, 239943, 329931, 715220, 1121505, 1300156, 1505499, 1741630, 2323520, 2679689, 3554345
Offset: 1

Views

Author

Omar E. Pol, Mar 22 2012

Keywords

Comments

Union of A154795 and A154798. The union of A209659 and this sequence gives A000041.

Crossrefs

A209659 Partition numbers p(n) having opposite parity of n.

Original entry on oeis.org

1, 5, 11, 30, 56, 77, 135, 176, 231, 385, 490, 627, 792, 1575, 1958, 3010, 6842, 8349, 17977, 26015, 75175, 89134, 124754, 147273, 281589, 386155, 451276, 526823, 614154, 831820, 966467, 2012558, 3087735, 5392783, 8118264, 9289091, 13848650
Offset: 1

Views

Author

Omar E. Pol, Mar 22 2012

Keywords

Comments

Union of A154797 and A154796. The union of this sequence and A209658 gives A000041.

Crossrefs

A193830 Even partition numbers of prime numbers.

Original entry on oeis.org

2, 56, 490, 6842, 124754, 831820, 13848650, 133230930, 214481126, 271248950, 541946240, 851376628, 5964539504, 11097645016, 37027355200, 45060624582, 142798995930, 207890420102, 625846753120, 1820701100652, 3068829878530, 37561133582570, 114540884553038
Offset: 1

Views

Author

Omar E. Pol, Aug 06 2011

Keywords

Examples

			The even number 56 is in the sequence as the partition number of the prime number 11.
		

Crossrefs

Programs

  • Mathematica
    Select[PartitionsP[Prime[Range[200]]],EvenQ] (* Harvey P. Dale, Jun 20 2015 *)
Previous Showing 11-20 of 22 results. Next