A000726
Number of partitions of n in which no parts are multiples of 3.
Original entry on oeis.org
1, 1, 2, 2, 4, 5, 7, 9, 13, 16, 22, 27, 36, 44, 57, 70, 89, 108, 135, 163, 202, 243, 297, 355, 431, 513, 617, 731, 874, 1031, 1225, 1439, 1701, 1991, 2341, 2731, 3197, 3717, 4333, 5022, 5834, 6741, 7803, 8991, 10375, 11923, 13716, 15723, 18038, 20628, 23603
Offset: 0
There are a(6)=7 partitions of 6 into parts != 0 (mod 3):
[ 1] [5,1],
[ 2] [4,2],
[ 3] [4,1,1],
[ 4] [2,2,2],
[ 5] [2,2,1,1],
[ 6] [2,1,1,1,1], and
[ 7] [1,1,1,1,1,1]
.
From _Joerg Arndt_, Dec 29 2012: (Start)
There are a(10)=22 partitions p(1)+p(2)+...+p(m)=10 such that p(k)!=p(k-2) (that is, no part appears more than twice):
[ 1] [ 3 3 2 1 1 ]
[ 2] [ 3 3 2 2 ]
[ 3] [ 4 2 2 1 1 ]
[ 4] [ 4 3 2 1 ]
[ 5] [ 4 3 3 ]
[ 6] [ 4 4 1 1 ]
[ 7] [ 4 4 2 ]
[ 8] [ 5 2 2 1 ]
[ 9] [ 5 3 1 1 ]
[10] [ 5 3 2 ]
[11] [ 5 4 1 ]
[12] [ 5 5 ]
[13] [ 6 2 1 1 ]
[14] [ 6 2 2 ]
[15] [ 6 3 1 ]
[16] [ 6 4 ]
[17] [ 7 2 1 ]
[18] [ 7 3 ]
[19] [ 8 1 1 ]
[20] [ 8 2 ]
[21] [ 9 1 ]
[22] [ 10 ]
(End)
- G. E. Andrews, The Theory of Partitions, Addison-Wesley, 1976, p. 109.
- L. Carlitz, Generating functions and partition problems, pp. 144-169 of A. L. Whiteman, ed., Theory of Numbers, Proc. Sympos. Pure Math., 8 (1965). Amer. Math. Soc., see p. 145.
- N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
- T. D. Noe and Vaclav Kotesovec, Table of n, a(n) for n = 0..5000 (terms 0..1000 from T. D. Noe)
- George E. Andrews, Partition Identities for Two-Color Partitions, Hardy-Ramanujan Journal, Hardy-Ramanujan Society, 2021, Special Commemorative volume in honour of Srinivasa Ramanujan, 2021, 44, pp.74-80. hal-03498190. See p. 79.
- Riccardo Aragona, Roberto Civino, and Norberto Gavioli, A modular idealizer chain and unrefinability of partitions with repeated parts, arXiv:2301.06347 [math.RA], 2023.
- N. Chair, Partition identities from Partial Supersymmetry, arXiv:hep-th/0409011, 2004.
- Edray Herber Goins and Talitha M. Washington, On the generalized climbing stairs problem, Ars Combin. 117 (2014), 183-190. MR3243840 (Reviewed), arXiv:0909.5459 [math.CO], 2009.
- Vaclav Kotesovec, A method of finding the asymptotics of q-series based on the convolution of generating functions, arXiv:1509.08708 [math.CO], Sep 30 2015, p. 15.
- Eric Weisstein's World of Mathematics, Partition function b_k.
- Wikipedia, Glaisher's Theorem.
Number of r-regular partitions for r = 2 through 12:
A000009,
A000726,
A001935,
A035959,
A219601,
A035985,
A261775,
A104502,
A261776,
A328545,
A328546.
-
a000726 n = p a001651_list n where
p _ 0 = 1
p ks'@(k:ks) m | m < k = 0
| otherwise = p ks' (m - k) + p ks m
-- Reinhard Zumkeller, Aug 23 2011
-
g:=product(1+x^j+x^(2*j),j=1..60): gser:=series(g,x=0,55): seq(coeff(gser,x,n),n=0..50); # Emeric Deutsch, Apr 18 2006
# second Maple program:
with(numtheory):
a:= proc(n) option remember; `if`(n=0, 1, add(a(n-j)*add(
`if`(irem(d, 3)=0, 0, d), d=divisors(j)), j=1..n)/n)
end:
seq(a(n), n=0..50); # Alois P. Heinz, Nov 17 2017
-
f[0] = 1; f[n_] := Coefficient[Expand@ Product[1 + x^k + x^(2k), {k, n}], x^n]; Table[f@n, {n, 0, 40}] (* Robert G. Wilson v, Nov 10 2006 *)
QP = QPochhammer; CoefficientList[QP[q^3]/QP[q] + O[q]^60, q] (* Jean-François Alcover, Nov 24 2015 *)
nmax = 50; CoefficientList[Series[Product[(1 - x^(3*k))/(1 - x^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Jan 02 2016 *)
Table[Count[IntegerPartitions@n, x_ /; ! MemberQ [Mod[x, 3], 0, 2] ], {n, 0, 50}] (* Robert Price, Jul 28 2020 *)
Table[Count[IntegerPartitions[n],?(NoneTrue[Mod[#,3]==0&])],{n,0,50}] (* _Harvey P. Dale, Sep 06 2022 *)
-
a(n)=if(n<0,0,polcoeff(eta(x^3+x*O(x^n))/eta(x+x*O(x^n)),n))
-
lista(nn) = {q='q+O('q^nn); Vec(eta(q^3)/eta(q))} \\ Altug Alkan, Mar 20 2018
A210485
Number T(n,k) of parts in all partitions of n in which no part occurs more than k times; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
0, 0, 1, 0, 1, 3, 0, 3, 3, 6, 0, 3, 8, 8, 12, 0, 5, 11, 15, 15, 20, 0, 8, 17, 24, 29, 29, 35, 0, 10, 23, 36, 41, 47, 47, 54, 0, 13, 36, 50, 65, 71, 78, 78, 86, 0, 18, 48, 75, 91, 104, 111, 119, 119, 128, 0, 25, 69, 102, 132, 150, 165, 173, 182, 182, 192
Offset: 0
T(6,2) = 17: [6], [5,1], [4,2], [3,3], [4,1,1], [3,2,1], [2,2,1,1].
Triangle T(n,k) begins:
0;
0, 1;
0, 1, 3;
0, 3, 3, 6;
0, 3, 8, 8, 12;
0, 5, 11, 15, 15, 20;
0, 8, 17, 24, 29, 29, 35;
0, 10, 23, 36, 41, 47, 47, 54;
0, 13, 36, 50, 65, 71, 78, 78, 86;
...
Columns k=0-10 give:
A000004,
A015723,
A185350,
A117148,
A320607,
A320608,
A320609,
A320610,
A320611,
A320612,
A320613.
-
b:= proc(n, i, k) option remember; `if`(n=0, [1, 0], `if`(i<1, [0, 0],
add((l->[l[1], l[2]+l[1]*j])(b(n-i*j, i-1, k)), j=0..min(n/i, k))))
end:
T:= (n, k)-> b(n, n, k)[2]:
seq(seq(T(n, k), k=0..n), n=0..12);
-
b[n_, i_, k_] := b[n, i, k] = If[n == 0, {1, 0}, If[i < 1, {0, 0}, Sum[b[n-i*j, i-1, k] /. l_List :> {l[[1]], l[[2]] + l[[1]]*j}, {j, 0, Min[n/i, k]}]]]; T[n_, k_] := b[n, n, k][[2]]; Table[Table[T[n, k], {k, 0, n}], {n, 0, 12}] // Flatten (* Jean-François Alcover, Dec 27 2013, translated from Maple *)
A290307
Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 + x^j)/(1 + x^(k*j)).
Original entry on oeis.org
1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 2, 1, 1, 0, 1, 1, 1, 2, 1, 2, 1, 0, 1, 1, 1, 2, 2, 2, 2, 1, 0, 1, 1, 1, 2, 2, 2, 3, 3, 2, 0, 1, 1, 1, 2, 2, 3, 3, 3, 3, 2, 0, 1, 1, 1, 2, 2, 3, 3, 4, 4, 3, 2, 0, 1, 1, 1, 2, 2, 3, 4, 4, 4, 5, 4, 2, 0, 1, 1, 1, 2, 2, 3, 4, 4, 5, 6, 6, 5, 3, 0
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
0, 1, 1, 1, 1, 1, ...
0, 0, 1, 1, 1, 1, ...
0, 1, 1, 2, 2, 2, ...
0, 1, 1, 1, 2, 2, ...
0, 1, 2, 2, 2, 3, ...
-
Table[Function[k, SeriesCoefficient[Product[(1 + x^i)/(1 + x^(i k)), {i, Infinity}], {x, 0, n}]][j - n + 1], {j, 0, 13}, {n, 0, j}] // Flatten
Table[Function[k, SeriesCoefficient[QPochhammer[-1, x]/QPochhammer[-1, x^k], {x, 0, n}]][j - n + 1], {j, 0, 13}, {n, 0, j}] // Flatten
A061198
Square table by antidiagonals where T(n,k) is number of partitions of k where no part appears more than n times; also partitions of k where no parts are multiples of (n+1).
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 0, 2, 2, 1, 1, 0, 2, 2, 2, 1, 1, 0, 3, 4, 3, 2, 1, 1, 0, 4, 5, 4, 3, 2, 1, 1, 0, 5, 7, 6, 5, 3, 2, 1, 1, 0, 6, 9, 9, 6, 5, 3, 2, 1, 1, 0, 8, 13, 12, 10, 7, 5, 3, 2, 1, 1, 0, 10, 16, 16, 13, 10, 7, 5, 3, 2, 1, 1, 0, 12, 22, 22, 19, 14, 11, 7, 5, 3, 2, 1, 1, 0, 15, 27, 29, 25, 20, 14, 11, 7, 5, 3, 2, 1, 1
Offset: 0
Square table T(n,k) begins:
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ...
1, 1, 1, 2, 2, 3, 4, 5, 6, 8, 10, ...
1, 1, 2, 2, 4, 5, 7, 9, 13, 16, 22, ...
1, 1, 2, 3, 4, 6, 9, 12, 16, 22, 29, ...
1, 1, 2, 3, 5, 6, 10, 13, 19, 25, 34, ...
1, 1, 2, 3, 5, 7, 10, 14, 20, 27, 37, ...
1, 1, 2, 3, 5, 7, 11, 14, 21, 28, 39, ...
1, 1, 2, 3, 5, 7, 11, 15, 21, 29, 40, ...
1, 1, 2, 3, 5, 7, 11, 15, 22, 29, 41, ...
1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 41, ...
1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, ...
A061199 is the same table but excluding cases where n>k.
-
b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(b(n-i*j, i-1, k), j=0..min(n/i, k))))
end:
A:= (n, k)-> b(k$2, n):
seq(seq(A(n, d-n), n=0..d), d=0..13); # Alois P. Heinz, Jan 26 2023
-
b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i<1, 0, Sum[b[n-i*j, i-1, k], {j, 0, Min[n/i, k]}]]];
A[n_, k_] := b[k, k, n];
Table[Table[A[n, d-n], {n, 0, d}], {d, 0, 13}] // Flatten (* Jean-François Alcover, Feb 11 2023, after Alois P. Heinz *)
A341714
Coefficients in the expansion of Product_{m>=1} (1 - q^(13*m))/(1 - q^m).
Original entry on oeis.org
1, 1, 2, 3, 5, 7, 11, 15, 22, 30, 42, 56, 77, 100, 134, 174, 228, 292, 378, 479, 612, 770, 972, 1213, 1519, 1881, 2334, 2874, 3540, 4331, 5302, 6450, 7848, 9501, 11496, 13851, 16680, 20006, 23980, 28648, 34193, 40689, 48378, 57360, 67948, 80295, 94788, 111652, 131388, 154293
Offset: 0
A304625
a(n) = [x^n] Product_{k>=1} ((1 - x^(n*k))/(1 - x^k))^n.
Original entry on oeis.org
1, 0, 3, 19, 101, 501, 2486, 12398, 62329, 315436, 1605330, 8207552, 42124368, 216903051, 1119974861, 5796944342, 30068145889, 156250892593, 813310723907, 4239676354631, 22130265931880, 115654632452514, 605081974091853, 3168828466966365, 16610409114771876, 87141919856550506
Offset: 0
Cf.
A000065,
A008485,
A022567,
A093160,
A270913,
A285927,
A285928,
A286653,
A296044,
A296162,
A296163,
A304626.
-
Table[SeriesCoefficient[Product[((1 - x^(n k))/(1 - x^k))^n, {k, 1, n}], {x, 0, n}], {n, 0, 25}]
Table[SeriesCoefficient[Product[1/(1 - x^k)^n, {k, 1, n - 1}], {x, 0, n}], {n, 0, 25}]
A286656
Square array A(n,k), n>=0, k>=1, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 - x^j)/(1 - x^(k*j)).
Original entry on oeis.org
1, 1, 0, 1, -1, 0, 1, -1, 0, 0, 1, -1, -1, -1, 0, 1, -1, -1, 1, 1, 0, 1, -1, -1, 0, -1, -1, 0, 1, -1, -1, 0, 1, 0, 1, 0, 1, -1, -1, 0, 0, 0, 2, -1, 0, 1, -1, -1, 0, 0, 2, -1, -1, 2, 0, 1, -1, -1, 0, 0, 1, -1, 1, -1, -2, 0, 1, -1, -1, 0, 0, 1, 1, 0, 2, 3, 2, 0, 1
Offset: 0
Square array begins:
1, 1, 1, 1, 1, ...
0, -1, -1, -1, -1, ...
0, 0, -1, -1, -1, ...
0, -1, 1, 0, 0, ...
0, 1, -1, 1, 0, ...
A302233
Square array A(n,k), n >= 0, k >= 1, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 + x^(k*j))/(1 + x^j).
Original entry on oeis.org
1, 1, 0, 1, -1, 0, 1, -1, 1, 0, 1, -1, 0, -2, 0, 1, -1, 0, 0, 2, 0, 1, -1, 0, -1, 0, -3, 0, 1, -1, 0, -1, 2, -1, 4, 0, 1, -1, 0, -1, 1, -2, 1, -5, 0, 1, -1, 0, -1, 1, 0, 1, -1, 6, 0, 1, -1, 0, -1, 1, -1, 0, -2, 1, -8, 0, 1, -1, 0, -1, 1, -1, 2, -1, 4, 0, 10, 0, 1, -1, 0, -1, 1, -1, 1, -2, 1, -4, 0, -12, 0
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
0, -1, -1, -1, -1, -1, ...
0, 1, 0, 0, 0, 0, ...
0, -2, 0, -1, -1, -1, ...
0, 2, 0, 2, 1, 1, ...
0, -3, -1, -2, 0, -1, ...
-
Table[Function[k, SeriesCoefficient[Product[(1 + x^(k i))/(1 + x^i), {i, 1, n}], {x, 0, n}]][j - n + 1], {j, 0, 12}, {n, 0, j}] // Flatten
Table[Function[k, SeriesCoefficient[QPochhammer[-1, x^k]/QPochhammer[-1, x], {x, 0, n}]][j - n + 1], {j, 0, 12}, {n, 0, j}] // Flatten
Showing 1-8 of 8 results.
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