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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A316210 Number of integer partitions of the n-th Fermi-Dirac prime into Fermi-Dirac primes.

Original entry on oeis.org

1, 1, 2, 2, 4, 7, 11, 17, 31, 37, 54, 109, 152, 283, 380, 878, 1482, 1906, 3101, 3924, 6197, 11915, 14703, 27063, 40016, 48450, 84633, 101419, 121250, 204461, 398916, 551093, 646073, 883626, 1030952, 1397083, 2522506, 3875455, 5128718, 7741307, 8860676
Offset: 1

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Author

Gus Wiseman, Jun 26 2018

Keywords

Comments

A Fermi-Dirac prime (A050376) is a number of the form p^(2^k) where p is prime and k >= 0.

Examples

			The a(6) = 7 partitions of 9 into Fermi-Dirac primes are (9), (54), (72), (333), (432), (522), (3222).
		

Crossrefs

Programs

  • Mathematica
    nn=60;
    FDpQ[n_]:=With[{f=FactorInteger[n]},n>1&&Length[f]==1&&MatchQ[FactorInteger[2f[[1,2]]],{{2,_}}]]
    FDprimeList=Select[Range[nn],FDpQ];
    ser=Product[1/(1-x^d),{d,FDprimeList}];
    Table[SeriesCoefficient[ser,{x,0,FDprimeList[[n]]}],{n,Length[FDprimeList]}]

A316211 Number of strict integer partitions of n into Fermi-Dirac primes.

Original entry on oeis.org

1, 0, 1, 1, 1, 2, 1, 3, 1, 4, 2, 4, 4, 4, 6, 4, 9, 5, 10, 8, 11, 11, 12, 15, 13, 19, 16, 21, 21, 24, 26, 27, 32, 31, 37, 37, 42, 44, 47, 52, 53, 61, 61, 69, 71, 78, 82, 88, 95, 99, 108, 112, 122, 128, 137, 144, 154, 163, 172, 184, 193, 206, 216, 230, 242, 256
Offset: 0

Views

Author

Gus Wiseman, Jun 26 2018

Keywords

Comments

A Fermi-Dirac prime (A050376) is a number of the form p^(2^k) where p is prime and k >= 0.

Examples

			The a(16) = 9 strict integer partitions of 16 into Fermi-Dirac primes:
(16),
(9,7), (11,5), (13,3),
(7,5,4), (9,4,3), (9,5,2), (11,3,2),
(7,4,3,2).
		

Crossrefs

Programs

  • Mathematica
    nn=60;
    FDpQ[n_]:=With[{f=FactorInteger[n]},n>1&&Length[f]==1&&MatchQ[FactorInteger[2f[[1,2]]],{{2,_}}]]
    FDprimeList=Select[Range[nn],FDpQ];
    ser=Product[1+x^d,{d,FDprimeList}];
    Table[SeriesCoefficient[ser,{x,0,n}],{n,0,nn}]

Formula

O.g.f.: Product_d (1 + x^d) where the product is over all Fermi-Dirac primes (A050376).

A347419 Number of partitions of n into two or more distinct primes.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 1, 1, 1, 2, 0, 2, 1, 2, 2, 3, 1, 4, 2, 4, 4, 4, 4, 5, 5, 6, 5, 6, 6, 6, 8, 7, 9, 9, 9, 11, 10, 11, 13, 12, 13, 15, 14, 17, 16, 18, 18, 20, 21, 23, 22, 25, 25, 27, 30, 29, 32, 32, 34, 37, 38, 40, 42, 44, 45, 50, 49, 53, 55, 57, 60, 64, 66, 70, 71, 76, 78, 83, 86, 89, 93, 96
Offset: 1

Views

Author

Ayoub Saber Rguez, Aug 31 2021

Keywords

Comments

Every positive integer can be written as a sum of two or more distinct primes except 1,2,3,4,6 and 11.

Examples

			a(5) = 1: 2+3.
a(18) = 4: 11+7, 11+5+2, 13+5, 13+3+2.
		

Crossrefs

Programs

  • Maple
    h:= proc(n) h(n):=`if`(n<2, 0, `if`(isprime(n), n, h(n-1))) end:
    b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<2, 0,
          b(n, h(i-1))+b(n-i, h(min(n-i, i-1)))))
        end:
    a:= n-> b(n, h(n-1)):
    seq(a(n), n=1..100);  # Alois P. Heinz, Sep 03 2021
  • Mathematica
    m = 24; Rest @ CoefficientList[Series[Product[(1 + x^Prime[k]), {k, 1, m}], {x, 0, Prime[m]}], x] - Table[Boole @ PrimeQ[n], {n, 1, Prime[m]}] (* Amiram Eldar, Sep 03 2021 *)
  • Python
    from sympy import isprime, primerange
    from functools import cache
    @cache
    def A000586(n, k=None): # after Charles R Greathouse IV
        if k == None: k = n
        if n < 1: return int(n == 0)
        return sum(A000586(n-p, p-1) for p in primerange(1, k+1))
    def a(n): return A000586(n) - isprime(n)
    print([a(n) for n in range(1, 83)]) # Michael S. Branicky, Sep 03 2021

Formula

a(n) = A000586(n) - A010051(n).

A347550 Number of partitions of n into at most 2 distinct prime parts.

Original entry on oeis.org

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

Views

Author

Ilya Gutkovskiy, Sep 08 2021

Keywords

Crossrefs

Formula

a(n) = Sum_{k=0..2} A219180(n,k). - Alois P. Heinz, Sep 08 2021

A358010 Number of partitions of n into at most 5 distinct prime parts.

Original entry on oeis.org

1, 0, 1, 1, 0, 2, 0, 2, 1, 1, 2, 1, 2, 2, 2, 2, 3, 2, 4, 3, 4, 4, 4, 5, 5, 5, 6, 5, 6, 7, 6, 9, 7, 9, 9, 9, 11, 11, 11, 13, 12, 13, 15, 15, 17, 15, 18, 17, 20, 20, 23, 20, 25, 22, 27, 28, 28, 27, 30, 29, 36, 34, 38, 36, 41, 35, 48, 41, 48, 44, 50, 46, 58, 53, 61, 54, 64, 55, 72, 66, 74
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 24 2022

Keywords

Crossrefs

A358011 Number of partitions of n into at most 6 distinct prime parts.

Original entry on oeis.org

1, 0, 1, 1, 0, 2, 0, 2, 1, 1, 2, 1, 2, 2, 2, 2, 3, 2, 4, 3, 4, 4, 4, 5, 5, 5, 6, 5, 6, 7, 6, 9, 7, 9, 9, 9, 11, 11, 11, 13, 12, 14, 15, 15, 17, 16, 18, 19, 20, 21, 23, 22, 25, 26, 27, 30, 29, 32, 31, 35, 36, 39, 40, 42, 42, 45, 49, 50, 52, 55, 53, 61, 61, 67, 67, 70, 70, 77, 77, 86, 84
Offset: 0

Views

Author

Ilya Gutkovskiy, Oct 24 2022

Keywords

Crossrefs

Programs

  • Maple
    P:= select(isprime,[2,seq(i,i=3..100,2)]):
    G:= mul(1+t*x^p, p=P):
    f:= proc(n) local i,S;
       S:= coeff(G,x,n);
       add(coeff(S,t,i),i=0..6)
    end proc;
    map(f, [$0..100]); # Robert Israel, May 14 2025

Formula

a(n) = Sum_{k=0..6} A219180(n,k). - Alois P. Heinz, May 14 2025

A141272 Number of partitions of n into distinct nonzero Mancala numbers (A007952).

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 0, 1, 2, 1, 1, 2, 1, 2, 2, 1, 3, 2, 1, 3, 3, 2, 2, 2, 3, 4, 2, 2, 5, 4, 3, 4, 5, 5, 4, 4, 5, 7, 4, 3, 8, 7, 5, 6, 6, 8, 9, 5, 7, 12, 7, 7, 10, 8, 11, 9, 8, 14, 13, 9, 12, 16, 13, 13, 13, 14, 18, 14, 12, 17, 19, 14, 16, 20, 17, 20, 19, 18, 25, 21, 18, 25, 24, 21
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 21 2008

Keywords

Examples

			a(20) = #{17+3, 11+9, 11+5+3+1} = 3;
a(21) = #{21, 17+3+1, 11+9+1} = 3;
a(22) = #{21+1, 17+5} = 2.
		

Crossrefs

A164067 Number of partitions of n into distinct Sophie Germain primes.

Original entry on oeis.org

0, 1, 1, 0, 2, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 2, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 2, 1, 1, 2, 1, 1, 3, 0, 2, 2, 0, 3, 1, 2, 2, 2, 2, 2, 2, 1, 2, 1, 1, 1, 2, 1, 2, 3, 1, 4, 2, 2, 3, 1, 2, 2, 2, 1, 3, 2, 2, 4, 2, 3, 3, 2, 2, 3, 1, 2, 3, 1, 3, 3, 2, 4, 3, 3, 4, 3, 3, 4, 3, 3, 4, 3, 5, 3, 5, 4, 4, 5, 3
Offset: 1

Views

Author

Reinhard Zumkeller, Aug 09 2009

Keywords

Examples

			e(16) = #{11+5, 11+3+2} = 2.
		

Crossrefs

Programs

  • PARI
    ok(n)={isprime(n) && isprime(2*n+1)}
    {my(n=80); Vec(prod(k=1, n, 1 + if(ok(k), x^k + O(x*x^n), 0))-1, -n)} \\ Andrew Howroyd, Dec 28 2017

Formula

G.f.: Product_{k>=1} (1 + x^A005384(k)). - Andrew Howroyd, Dec 28 2017

A208614 Number of partitions of n into distinct primes where all of the prime factors of n are represented in the partition.

Original entry on oeis.org

1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 3, 1, 4, 2, 1, 1, 1, 3, 2, 1, 1, 3, 1, 1, 2, 3, 1, 2, 1, 3, 4, 2, 1, 5, 9, 6, 5, 4, 1, 6, 6, 7, 4, 3, 1, 4, 1, 4, 9, 20, 7, 3, 1, 7, 8, 6, 1, 15, 1, 5, 19, 11, 13, 9, 1, 21, 52, 7, 1
Offset: 0

Views

Author

Richard Penner, Feb 29 2012

Keywords

Comments

Inspired by web-based discussion started by Rajesh Bhowmick.

Examples

			a(p) = 1 for any prime p.
a(n) = 0 for 1, 4, 6, 8, 9, 22.
a(25) = 3 because 25 = 3 + 5 + 17 = 5 + 7 + 13 = 2 + 5 + 7 + 11.
		

Crossrefs

Cf. A000586 (upper bound). A000586(A076694(n)) is a stricter upper bound.

Programs

  • Maple
    with(numtheory):
    a:= proc(n) local b, l, f;
          b:= proc(h, j) option remember;
                `if`(h=0, 1, `if`(j<1, 0,
                `if`(l[j]>h, 0, b(h-l[j], j-1)) +b(h, j-1)))
              end; forget(b);
          f:= factorset(n);
          l:= sort([({seq(ithprime(i), i=1..pi(n))} minus f)[]]);
          b(n-add(i, i=f), nops(l))
        end:
    seq(a(n), n=0..300);  # Alois P. Heinz, Mar 20 2012
  • Mathematica
    restrictedIntegerPartition[ n_Integer, list_List ] := 1 /; n == 0
    restrictedIntegerPartition[ n_Integer, list_List ] := 0 /; n < 0 || Total[list] < n || n < Min[list]
    restrictedIntegerPartition[ n_Integer, list_List ] := restrictedIntegerPartition[n - First[list], Rest[list]] + restrictedIntegerPartition[n, Rest[list]]
    distinctPrimeFactors[ n_Integer ] := distinctPrimeFactors[n] = Map[First, FactorInteger[n]]
    oeisA076694[ n_Integer ] := oeisA076694[n] = n - Total[distinctPrimeFactors[n]]
    oeisA208614[ n_Integer ] := restrictedIntegerPartition[oeisA076694[n], Sort[Complement[Prime @ Range @ PrimePi @ oeisA076694 @ n, distinctPrimeFactors[n]] , Greater ]]
    Table[oeisA208614[n], {n,1,100}]
  • Maxima
    countRestrictedIntegerPartitions(n, L) := if ( n = 0 ) then 1 else if ( ( n < 0 ) or ( lsum(k, k, L) < n ) or ( n < lmin( L ) ) ) then 0 else block( [ m, R ], m : first(L), R : rest(L), countRestrictedIntegerPartitions(n, R) + countRestrictedIntegerPartitions(n - m, R));
    distinctPrimeFactors(n) := map(first,ifactors(n));
    oeisA076694(n) := n - lsum(k,k,distinctPrimeFactors(n));
    listOfPrimesLessThanOrEqualTo (n) := block( [ list : [] , i], for i : 2 step 0 while i <= n do ( list : cons(i, list) , i : next_prime(i) ) , list );
    oeisA208614(n) := block([ m, list ], m : oeisA076694(n), list : sort(listify(setdifference(setify(listOfPrimesLessThanOrEqualTo(m)), setify(distinctPrimeFactors(n)))), ordergreatp), countRestrictedIntegerPartitions(m, list));
    makelist(oeisA208614(j), j, 1, 100);

A281274 Expansion of Product_{j>=1} (1 + x^(Sum_{i=1..j} prime(i))).

Original entry on oeis.org

1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 2, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 2, 0, 2, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 3, 0, 3, 0, 1, 2, 0, 2, 0, 0, 2, 1, 2, 1, 0, 2, 1, 3, 1, 2, 0, 2, 1, 1, 2, 0, 2, 1, 3, 2, 2, 1, 1, 2, 2, 2, 2, 0, 3, 0, 2, 2, 1, 4, 1, 3, 2, 3, 2, 2, 1, 2, 3
Offset: 0

Views

Author

Ilya Gutkovskiy, Jan 18 2017

Keywords

Comments

Number of partitions of n into distinct nonzero partial sums of primes (A007504).

Examples

			a(17) = 2 because we have [17] and [10, 5, 2], where 2 = prime(1), 5 = prime(1) + prime(2), 10 = prime(1) + prime(2) + prime(3), 17 = prime(1) + prime(2) + prime(3) + prime(4).
		

Crossrefs

Programs

  • Mathematica
    nmax = 110; CoefficientList[Series[Product[1 + x^Sum[Prime[i], {i, 1, j}], {j, 1, nmax}], {x, 0, nmax}], x]

Formula

G.f.: Product_{j>=1} (1 + x^(Sum_{i=1..j} prime(i))).
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