A286014
Sum of smallest parts of all partitions of n into consecutive parts.
Original entry on oeis.org
1, 2, 4, 4, 7, 7, 10, 8, 15, 11, 16, 15, 19, 16, 27, 16, 25, 26, 28, 22, 38, 26, 34, 31, 40, 31, 50, 29, 43, 49, 46, 32, 62, 41, 59, 48, 55, 46, 74, 46, 61, 67, 64, 46, 94, 56, 70, 63, 77, 69, 98, 55, 79, 85, 92, 61, 110, 71, 88, 93, 91, 76, 131, 64, 110, 103
Offset: 1
For n = 15 there are four partitions of 15 into consecutive parts: [15], [8, 7], [6, 5, 4] and [5, 4, 3, 2, 1]. The sum of the smallest parts is 15 + 7 + 4 + 1 = 27, so a(15) = 27.
-
Table[Total[Select[IntegerPartitions@ n, Or[Length@ # == 1, Union@ Differences@ # == {-1}] &][[All, -1]]], {n, 66}] (* Michael De Vlieger, Jul 21 2017 *)
A286015
Sum of largest parts of all partitions of n into consecutive parts.
Original entry on oeis.org
1, 2, 5, 4, 8, 9, 11, 8, 18, 14, 17, 17, 20, 19, 34, 16, 26, 31, 29, 26, 46, 29, 35, 33, 45, 34, 58, 35, 44, 58, 47, 32, 70, 44, 70, 57, 56, 49, 82, 50, 62, 78, 65, 53, 114, 59, 71, 65, 84, 76, 106, 62, 80, 98, 106, 67, 118, 74, 89, 106, 92, 79, 153, 64, 124
Offset: 1
For n = 15 there are four partitions of 15 into consecutive parts: [15], [8, 7], [6, 5, 4] and [5, 4, 3, 2, 1]. The sum of the largest parts is 15 + 8 + 6 + 5 = 34, so a(15) = 34.
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Table[Total[Select[IntegerPartitions@ n, Or[Length@ # == 1, Union@ Differences@ # == {-1}] &][[All, 1]]], {n, 65}] (* Michael De Vlieger, Jul 21 2017 *)
A097145
Total sum of minimum list sizes in all sets of lists of n-set, cf. A000262.
Original entry on oeis.org
0, 1, 5, 25, 157, 1101, 9211, 85513, 900033, 10402633, 133059331, 1836961941, 27619253113, 444584808253, 7678546353843, 140944884572521, 2751833492404321, 56691826303303953, 1233793951629951043, 28191548364561422173, 676190806704598883241
Offset: 0
For n=4 we have 73 sets of lists (cf. A000262): (1234) (24 ways), (123)(4) (6*4 ways), (12)(34) (3*4 ways), (12)(3)(4) (6*2 ways), (1)(2)(3)(4) (1 way); so a(n)= 24*4+24*1+12*2+12*1+1*1 = 157.
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b:= proc(n, m) option remember; `if`(n=0, m, add(j!*
b(n-j, min(m, j))*binomial(n-1, j-1), j=1..n))
end:
a:= n-> `if`(n=0, 0, b(n, infinity)):
seq(a(n), n=0..25); # Alois P. Heinz, May 10 2016
-
b[n_, m_] := b[n, m] = If[n==0, m, Sum[j!*b[n-j, Min[m, j]]*Binomial[n-1, j - 1], {j, 1, n}]]; a[n_] := If[n==0, 0, b[n, Infinity]]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Feb 18 2017, after Alois P. Heinz *)
A182708
a(n) is the sum of the smallest parts of all partitions of n that do not contain 1 as a part.
Original entry on oeis.org
0, 2, 3, 6, 7, 13, 14, 23, 27, 39, 45, 67, 75, 104, 125, 165, 194, 258, 302, 392, 467, 588, 700, 885, 1045, 1296, 1546, 1897, 2249, 2753, 3252, 3945, 4670, 5616, 6633, 7957, 9357, 11157, 13124, 15573, 18257, 21599, 25259, 29760, 34760, 40788, 47526, 55642, 64669, 75465, 87576, 101898, 117991, 136977, 158286
Offset: 1
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Table[Total[{Min /@ IntegerPartitions[n, All, Range[2, n]]}, 2], {n, 55}] (* Robert Price, Aug 30 2020 *) (* Only suitable for n<100 *)
-
my(N=66, z='z+O('z^N)); gf=sum(k=1, N, k * z^k / prod(j=k, N, 1-z^j ) ) - z/eta(z); concat([0], Vec(gf)) \\ Joerg Arndt, Aug 31 2020
A182977
Total number of parts that are neither the smallest part nor the largest part in all partitions of n.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 1, 2, 6, 12, 22, 39, 66, 103, 159, 243, 352, 510, 721, 1011, 1391, 1903, 2557, 3436, 4549, 5999, 7824, 10187, 13132, 16886, 21544, 27414, 34657, 43703, 54797, 68558, 85328, 105963, 131028, 161664, 198710
Offset: 0
For n = 6 the partitions of 6 are
6
5 + 1
4 + 2
4 + 1 + 1
3 + 3
3 + (2) + 1 .......... the "2" is the part that counts.
3 + 1 + 1 + 1
2 + 2 + 2
2 + 2 + 1 + 1
2 + 1 + 1 + 1 + 1
1 + 1 + 1 + 1 + 1 + 1
There is only one part which is neither the smallest part nor the largest part in all partitions of 6, so a(6) = 1.
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g := add(add((add(x^(i+j+k)/(1-x^k), k = i+1 .. j-1))/(mul(1-x^k, k = i .. j)), j = i+1 .. 80), i = 1 .. 80): gser := series(g, x = 0, 50): seq(coeff(gser, x, n), n = 0 .. 45); # Emeric Deutsch, Dec 25 2015
a(12) corrected and more terms a(13)-a(40) from
David Scambler, Jul 18 2011
A097146
Total sum of maximum list sizes in all sets of lists of n-set, cf. A000262.
Original entry on oeis.org
0, 1, 5, 31, 217, 1781, 16501, 172915, 1998641, 25468777, 352751941, 5292123431, 85297925065, 1472161501981, 27039872306357, 527253067633531, 10865963240550241, 236088078855319505, 5390956470528548101, 129102989125943058607, 3234053809095307670201, 84596120521251178630981, 2305894874979300173268085
Offset: 0
For n=4 we have 73 sets of lists (cf. A000262): (1234) (24 ways), (123)(4) (6*4 ways), (12)(34) (3*4 ways), (12)(3)(4) (6*2 ways), (1)(2)(3)(4) (1 way); so a(4)= 24*4+24*3+12*2+12*2+1*1 = 217.
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b:= proc(n, m) option remember; `if`(n=0, m, add(j!*
b(n-j, max(m, j))*binomial(n-1, j-1), j=1..n))
end:
a:= n-> b(n, 0):
seq(a(n), n=0..25); # Alois P. Heinz, May 10 2016
-
b[n_, m_] := b[n, m] = If[n == 0, m, Sum[j! b[n-j, Max[m, j]] Binomial[n-1, j-1], {j, 1, n}]];
a[n_] := b[n, 0];
a /@ Range[0, 25] (* Jean-François Alcover, Nov 05 2020, after Alois P. Heinz *)
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N=50; x='x+O('x^N);
egf=exp(x/(1-x))*sum(k=1,N, (1-exp(x^k/(x-1))) );
Vec( serlaplace(egf) ) /* show terms */
A182978
Total number of parts that are the smallest part or the largest part in all partitions of n.
Original entry on oeis.org
1, 3, 6, 12, 20, 34, 52, 80, 116, 170, 236, 333, 453, 621, 825, 1111, 1455, 1923, 2487, 3239, 4149, 5342, 6770, 8625, 10852, 13698, 17107, 21413, 26567, 33019, 40721, 50270, 61663, 75665, 92318, 112686, 136849, 166173, 200923, 242836
Offset: 1
For n = 6 the partitions of 6 are
6
5 + 1
4 + 2
4 + 1 + 1
3 + 3
3 + (2) + 1 .... the "2" is the part that does not count.
3 + 1 + 1 + 1
2 + 2 + 2
2 + 2 + 1 + 1
2 + 1 + 1 + 1 + 1
1 + 1 + 1 + 1 + 1 + 1
The total number of parts in all partitions of 6 is equal to 35. All parts are the smallest part or the largest part, except the "2" in the partition (3 + 2 + 1), so a(6) = 35 - 1 = 34.
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l:= proc(n, i) option remember; `if`(n=i, n, 0)+
`if`(i<1, 0, l(n, i-1) +`if`(n l(n, n) +s(n, n) -numtheory[sigma](n):
seq(a(n), n=1..50); # Alois P. Heinz, Jan 17 2013
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l[n_, i_] := l[n, i] = If[n==i, n, 0] + If[i<1, 0, l[n, i-1] + If[nJean-François Alcover, Nov 03 2015, after Alois P. Heinz *)
a(12) corrected and more terms a(13)-a(40) from
David Scambler, Jul 18 2011
A182629
Total number of largest parts in all partitions of n that contain at least two distinct parts.
Original entry on oeis.org
0, 0, 0, 1, 2, 6, 8, 17, 23, 36, 51, 75, 95, 138, 181, 236, 310, 407, 516, 667, 840, 1062, 1344, 1678, 2080, 2589, 3212, 3942, 4851, 5937, 7246, 8824, 10724, 12971, 15705, 18895, 22749, 27296, 32734, 39083, 46668, 55553, 66086, 78389, 92937, 109857, 129850
Offset: 0
For n = 6 the partitions of 6 are
6 ....................... all parts are equal.
5 + 1 ................... contains only one largest part.
4 + 2 ................... contains only one largest part.
4 + 1 + 1 ............... contains only one largest part.
3 + 3 ................... all parts are equal.
3 + 2 + 1 ............... contains only one largest part.
3 + 1 + 1 + 1 ........... contains only one largest part.
2 + 2 + 2 ............... all parts are equal.
2 + 2 + 1 + 1 ........... contains two largest parts.
2 + 1 + 1 + 1 + 1 ....... contains only one largest part.
1 + 1 + 1 + 1 + 1 + 1 ... all parts are equal.
There are 8 largest parts, so a(6) = 8.
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b:= proc(n, i) option remember; `if`(n=i, n, 0)+
`if`(i<1, 0, b(n, i-1) +`if`(n b(n, n) -numtheory[sigma](n):
seq(a(n), n=0..100); # Alois P. Heinz, Jan 17 2013
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b[n_, i_] := b[n, i] = If[n == i, n, 0] + If[i < 1, 0, b[n, i - 1] + If[n < i, 0, b[n - i, i]]]; a[n_] := b[n, n] - DivisorSigma[1, n]; a[0] = 0; Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Feb 06 2017, after Alois P. Heinz *)
A196039
Total sum of the smallest part of every partition of every shell of n.
Original entry on oeis.org
0, 1, 4, 9, 18, 30, 50, 75, 113, 162, 231, 318, 441, 593, 798, 1058, 1399, 1824, 2379, 3066, 3948, 5042, 6422, 8124, 10264, 12884, 16138, 20120, 25027, 30994, 38312, 47168, 57955, 70974, 86733, 105676, 128516, 155850, 188644, 227783, 274541
Offset: 0
For n = 5 the seven partitions of 5 are:
5
3 + 2
4 + 1
2 + 2 + 1
3 + 1 + 1
2 + 1 + 1 + 1
1 + 1 + 1 + 1 + 1
.
The five shells of 5 (see A135010 and also A138121), written as a triangle, are:
1
2, 1
3, 1, 1
4, (2, 2), 1, 1, 1
5, (3, 2), 1, 1, 1, 1, 1
.
The first "2" of row 4 does not count, also the "3" of row 5 does not count, so we have:
1
2, 1
3, 1, 1
4, 2, 1, 1, 1
5, 2, 1, 1, 1, 1, 1
.
thus a(5) = 1+2+1+3+1+1+4+2+1+1+1+5+2+1+1+1+1+1 = 30.
Cf.
A026905,
A046746,
A066186,
A135010,
A138121,
A182699,
A182707,
A182709,
A183152,
A193827,
A196025,
A196930,
A196931,
A198381,
A206437.
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b:= proc(n, i) option remember;
`if`(n=i, n, 0) +`if`(i<1, 0, b(n, i-1) +`if`(nAlois P. Heinz, Apr 03 2012
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b[n_, i_] := b[n, i] = If[n == i, n, 0] + If[i < 1, 0, b[n, i-1] + If[n < i, 0, b[n-i, i]]]; Accumulate[Table[b[n, n], {n, 0, 50}]] (* Jean-François Alcover, Feb 05 2017, after Alois P. Heinz *)
A225598
Triangle read by rows: T(n,k) = sum of all parts of all regions of the set of partitions of n whose largest part is k.
Original entry on oeis.org
1, 1, 3, 1, 3, 5, 1, 5, 5, 9, 1, 5, 8, 9, 12, 1, 7, 11, 15, 12, 20, 1, 7, 14, 19, 19, 20, 25, 1, 9, 17, 29, 24, 33, 25, 38, 1, 9, 23, 33, 36, 42, 39, 38, 49, 1, 11, 26, 47, 46, 61, 49, 61, 49, 69, 1, 11, 32, 55, 63, 76, 70, 76, 76, 69, 87, 1, 13, 38, 73, 78, 110, 87, 111, 95, 108, 87, 123
Offset: 1
For n = 5 and k = 3 the set of partitions of 5 contains two regions whose largest part is 3, they are third region which contains three parts [3, 1, 1] and the sixth region which contains only one part [3]. Therefore the sum of all parts is 3 + 1 + 1 + 3 = 8, so T(5,3) = 8.
.
. Diagram Illustration of parts ending in column k:
. for n=5 k=1 k=2 k=3 k=4 k=5
. _ _ _ _ _ _ _ _ _ _
. |_ _ _ | _ _ _ |_ _ _ _ _|
. |_ _ _|_ | |_ _ _| _ _ _ _ |_ _|
. |_ _ | | _ _ |_ _ _ _| |_|
. |_ _|_ | | |_ _| _ _ _ |_ _| |_|
. |_ _ | | | _ _ |_ _ _| |_| |_|
. |_ | | | | _ |_ _| |_| |_| |_|
. |_|_|_|_|_| |_| |_| |_| |_| |_|
.
k = 1 2 3 4 5
.
The 5th row lists: 1 5 8 9 12
.
Triangle begins:
1;
1, 3;
1, 3, 5;
1, 5, 5, 9;
1, 5, 8, 9, 12;
1, 7, 11, 15, 12, 20;
1, 7, 14, 19, 19, 20, 25;
1, 9, 17, 29, 24, 33, 25, 38;
1, 9, 23, 33, 36, 42, 39, 38, 49;
1, 11, 26, 47, 46, 61, 49, 61, 49, 69;
1, 11, 32, 55, 63, 76, 70, 76, 76, 69, 87;
1, 13, 38, 73, 78, 110, 87, 111, 95, 108, 87, 123;
Cf.
A000041,
A066186,
A135010,
A141285,
A186114,
A186412,
A187219,
A194446,
A206437,
A207779,
A211978,
A225597,
A225600,
A225610.
Comments