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.

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

A163997 Primes with an even number of partitions.

Original entry on oeis.org

2, 11, 19, 31, 47, 59, 79, 97, 101, 103, 109, 113, 131, 137, 149, 151, 163, 167, 179, 191, 197, 227, 241, 271, 307, 317, 337, 347, 353, 359, 379, 383, 397, 409, 419, 431, 439, 449, 487, 503, 509, 521, 523, 541, 557, 563, 569, 571, 577, 599, 607, 631, 641, 643
Offset: 1

Views

Author

Omar E. Pol, Aug 09 2009

Keywords

Examples

			11 is in the sequence because the number of partitions of 11 is equal to 56 and 56 is an even number.
		

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[200]],EvenQ[PartitionsP[#]]&] (* Harvey P. Dale, Jul 01 2019 *)

Extensions

More terms from Sean A. Irvine, Oct 18 2009

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

A163996 Primes with a composite number of partitions.

Original entry on oeis.org

7, 11, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293
Offset: 1

Views

Author

Omar E. Pol, Aug 09 2009

Keywords

Crossrefs

Programs

  • Mathematica
    Select[Prime[Range[100]],!PrimeQ[PartitionsP[#]]&] (* Harvey P. Dale, Jun 22 2014 *)

Formula

A000040 \ A038601. [From R. J. Mathar, Sep 27 2009]

Extensions

More terms from R. J. Mathar, Sep 27 2009

A193831 Odd partition numbers of prime numbers.

Original entry on oeis.org

3, 7, 15, 101, 297, 1255, 4565, 21637, 44583, 63261, 329931, 1121505, 2679689, 4697205, 6185689, 23338469, 49995925, 431149389, 3913864295, 13610949895, 80630964769, 362326859895, 749474411781, 2168627105469, 3646072432125, 10085065885767, 27152408925615
Offset: 1

Views

Author

Omar E. Pol, Aug 06 2011

Keywords

Examples

			The odd number 101 is in the sequence as the partition number of the prime number 13.
		

Crossrefs

Showing 1-5 of 5 results.