A072720
Number of partitions of n into parts which are each powers of a single number (which may vary between partitions).
Original entry on oeis.org
1, 1, 2, 3, 5, 6, 10, 11, 15, 17, 23, 24, 34, 35, 43, 47, 57, 58, 73, 74, 91, 96, 112, 113, 139, 141, 163, 168, 197, 198, 235, 236, 272, 279, 317, 321, 378, 379, 427, 436, 501, 502, 575, 576, 653, 666, 742, 743, 851, 853, 952, 963, 1080, 1081, 1211, 1216, 1361
Offset: 0
a(6)=10 since 6 can be written as 6 (powers of 6), 5+1 (5), 4+1+1 (4 or 2), 3+3 (3), 3+1+1+1 (3), 4+2 (2), 2+2+2 (2), 2+2+1+1 (2), 2+1+1+1+1 (2) and 1+1+1+1+1+1 (powers of anything).
From _Gus Wiseman_, Jan 01 2019: (Start)
The a(1) = 1 through a(8) = 15 integer partitions:
(1) (2) (3) (4) (5) (6) (7) (8)
(11) (21) (22) (41) (33) (61) (44)
(111) (31) (221) (42) (331) (71)
(211) (311) (51) (421) (422)
(1111) (2111) (222) (511) (611)
(11111) (411) (2221) (2222)
(2211) (4111) (3311)
(3111) (22111) (4211)
(21111) (31111) (5111)
(111111) (211111) (22211)
(1111111) (41111)
(221111)
(311111)
(2111111)
(11111111)
(End)
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radbase[n_]:=n^(1/GCD@@FactorInteger[n][[All,2]]);
Table[Length[Select[IntegerPartitions[n],SameQ@@radbase/@DeleteCases[#,1]&]],{n,30}] (* Gus Wiseman, Jan 01 2019 *)
A292477
Square array A(n,k), n >= 0, k >= 2, read by antidiagonals: A(n,k) = [x^(k*n)] Product_{j>=0} 1/(1 - x^(k^j)).
Original entry on oeis.org
1, 1, 2, 1, 2, 4, 1, 2, 3, 6, 1, 2, 3, 5, 10, 1, 2, 3, 4, 7, 14, 1, 2, 3, 4, 6, 9, 20, 1, 2, 3, 4, 5, 8, 12, 26, 1, 2, 3, 4, 5, 7, 10, 15, 36, 1, 2, 3, 4, 5, 6, 9, 12, 18, 46, 1, 2, 3, 4, 5, 6, 8, 11, 15, 23, 60, 1, 2, 3, 4, 5, 6, 7, 10, 13, 18, 28, 74, 1, 2, 3, 4, 5, 6, 7, 9, 12, 15, 21, 33, 94
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
2, 2, 2, 2, 2, 2, ...
4, 3, 3, 3, 3, 3, ...
6, 5, 4, 4, 4, 4, ...
10, 7, 6, 5, 5, 5, ...
14, 9, 8, 7, 6, 6, ...
Mirror of
A089688 (excluding the first row).
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Table[Function[k, SeriesCoefficient[Product[1/(1 - x^k^i), {i, 0, n}], {x, 0, k n}]][j - n + 2], {j, 0, 12}, {n, 0, j}] // Flatten
A309677
G.f. A(x) satisfies: A(x) = A(x^3) / (1 - x)^2.
Original entry on oeis.org
1, 2, 3, 6, 9, 12, 18, 24, 30, 42, 54, 66, 87, 108, 129, 162, 195, 228, 279, 330, 381, 456, 531, 606, 711, 816, 921, 1068, 1215, 1362, 1563, 1764, 1965, 2232, 2499, 2766, 3120, 3474, 3828, 4290, 4752, 5214, 5805, 6396, 6987, 7740, 8493, 9246, 10194, 11142
Offset: 0
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b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<0, 0,
b(n, i-1)+(p-> `if`(p>n, 0, b(n-p, i)))(3^i)))
end:
a:= n-> add(b(j, ilog[3](j))*b(n-j, ilog[3](n-j)), j=0..n):
seq(a(n), n=0..52); # Alois P. Heinz, Aug 12 2019
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nmax = 52; A[] = 1; Do[A[x] = A[x^3]/(1 - x)^2 + O[x]^(nmax + 1) // Normal, nmax + 1]; CoefficientList[A[x], x]
nmax = 52; CoefficientList[Series[Product[1/(1 - x^(3^k))^2, {k, 0, Floor[Log[3, nmax]] + 1}], {x, 0, nmax}], x]
A371709
Expansion of g.f. A(x) satisfying A( x*A(x)^2 + x*A(x)^3 ) = A(x)^3.
Original entry on oeis.org
1, 1, 1, 2, 6, 16, 39, 99, 271, 764, 2157, 6128, 17658, 51534, 151635, 448962, 1337493, 4008040, 12072594, 36524898, 110943633, 338218626, 1034509917, 3173811240, 9763898994, 30113782641, 93094164244, 288415278638, 895332445053, 2784580242557, 8675408291598, 27072326322939
Offset: 1
G.f. A(x) = x + x^2 + x^3 + 2*x^4 + 6*x^5 + 16*x^6 + 39*x^7 + 99*x^8 + 271*x^9 + 764*x^10 + 2157*x^11 + 6128*x^12 + 17658*x^13 + 51534*x^14 + 151635*x^15 + 448962*x^16 + ...
where A( x*A(x)^2*(1 + A(x)) ) = A(x)^3.
RELATED SERIES.
A(x)^2 = x^2 + 2*x^3 + 3*x^4 + 6*x^5 + 17*x^6 + 48*x^7 + 126*x^8 + 332*x^9 + 918*x^10 + 2616*x^11 + 7504*x^12 + ...
A(x)^3 = x^3 + 3*x^4 + 6*x^5 + 13*x^6 + 36*x^7 + 105*x^8 + 292*x^9 + 801*x^10 + 2256*x^11 + 6515*x^12 + 18981*x^13 + ...
A(x)^2 + A(x)^3 = x^2 + 3*x^3 + 6*x^4 + 12*x^5 + 30*x^6 + 84*x^7 + 231*x^8 + 624*x^9 + 1719*x^10 + 4872*x^11 + 14019*x^12 + 40599*x^13 + ...
Let B(x) be the series reversion of g.f. A(x), B(A(x)) = x, then
B(x) * (1+x)/(1+x^3) = x - 2*x^4 + 3*x^7 - 5*x^10 + 7*x^13 - 9*x^16 + 12*x^19 - 15*x^22 + 18*x^25 - 23*x^28 + ... + (-1)^n*A005704(n)*x^(3*n+1) + ...
where A005704 is the number of partitions of 3*n into powers of 3.
We can show that g.f. A(x) = A( x*A(x)^2*(1 + A(x)) )^(1/3) satisfies
(4) A(x) = x * Product_{n>=0} (1 + A(x)^(3^n))
by substituting x*A(x)^2*(1 + A(x)) for x in (4) to obtain
A(x)^3 = x * A(x)^2*(1 + A(x)) * Product_{n>=1} (1 + A(x)^(3^n))
which is equivalent to formula (4).
SPECIFIC VALUES.
A(3/10) = 0.526165645044542830201162330432965674027415264612114520...
A(1/4) = 0.353259384374080248921564026412797625837830114153200664...
A(1/5) = 0.255218141344695821239609680309162895225297482063273545...
A(t) = 1/2 and A(t*3/8) = 1/8 at t = (1/2)/Product_{n>=0} (1 + 1/2^(3^n)) = 0.295718718466711580562679377308518930409875701753934072...
A(t) = 1/3 and A(t*4/27) = 1/27 at t = (1/3)/Product_{n>=0} (1 + 1/3^(3^n)) = 0.241059181496179959557718992589733756750585121455883861...
A(t) = 1/4 and A(t*5/64) = 1/64 at t = (1/4)/Product_{n>=0} (1 + 1/4^(3^n)) = 0.196922325724019432212969925740117827612003158137366017...
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/* Using series reversion of x/Product_{n>=0} (1 + x^(3^n)) */
{a(n) = my(A); A = serreverse( x/prod(k=0,ceil(log(n)/log(3)), (1 + x^(3^k) +x*O(x^n)) ) ); polcoeff(A,n)}
for(n=1,35, print1(a(n),", "))
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/* Using A(x)^3 = A( x*A(x)^2 + x*A(x)^3 ) */
{a(n) = my(A=[1],F); for(i=1,n, A = concat(A,0); F = x*Ser(A);
A[#A] = polcoeff( subst(F,x, x*F^2 + x*F^3 ) - F^3, #A+2) ); A[n]}
for(n=1,35, print1(a(n),", "))
A089649
a(1)=1, a(2)=2, a(n) = a(n-1) + a(floor((n+1)/3)).
Original entry on oeis.org
1, 2, 3, 4, 6, 8, 10, 13, 16, 19, 23, 27, 31, 37, 43, 49, 57, 65, 73, 83, 93, 103, 116, 129, 142, 158, 174, 190, 209, 228, 247, 270, 293, 316, 343, 370, 397, 428, 459, 490, 527, 564, 601, 644, 687, 730, 779, 828, 877, 934, 991, 1048, 1113, 1178, 1243, 1316, 1389
Offset: 1
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Fold[Append[#1, #1[[-1]] + #1[[Quotient[#2 + 1, 3]]]] &, {1, 2}, Range[3, 57]] (* Ivan Neretin, Nov 25 2016 *)
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a(n)=if(n<2,1,a(n-1)+a(floor((n+1)/3)))
A183038
G.f.: exp( Sum_{n>=1} A051064(n)*3^A051064(n)*x^n/n ) where A051064(n) equals the 3-adic valuation of 3n.
Original entry on oeis.org
1, 3, 6, 15, 30, 51, 93, 156, 240, 387, 597, 870, 1311, 1920, 2697, 3873, 5448, 7422, 10278, 14016, 18636, 25098, 33402, 43548, 57333, 74757, 95820, 123780, 158637, 200391, 254778, 321798, 401451, 503490, 627915, 774726, 960156, 1184205, 1446873
Offset: 0
G.f.: A(x) = 1 + 3*x + 6*x^2 + 15*x^3 + 30*x^4 + 51*x^5 + 93*x^6 +...
log(A(x)) = 3*x + 3*x^2/2 + 18*x^3/3 + 3*x^4/4 + 3*x^5/5 + 18*x^6/6 + 3*x^7/7 + 3*x^8/8 + 81*x^9/9 + 3*x^10/10 + 3*x^11/11 + 18*x^12/12 +...
G.f. satisfies A(x) = A(x^3)*G(x) where G(x) is the g.f. of A161809:
G(x) = 1 + 3*x + 6*x^2 + 12*x^3 + 21*x^4 + 33*x^5 + 51*x^6 +...
TRISECTIONS of g.f. begin:
T_0(x) = 1 + 15*x + 93*x^2 + 387*x^3 + 1311*x^4 + 3873*x^5 +...
T_1(x) = 3 + 30*x + 156*x^2 + 597*x^3 + 1920*x^4 + 5448*x^5 +...
T_2(x) = 6 + 51*x + 240*x^2 + 870*x^3 + 2697*x^4 + 7422*x^5 +...
where the ratios involve Fibonacci numbers:
T_1(x)/T_0(x) = 3*(1 - 5*x + 34*x^2 - 233*x^3 +...+ (-1)^n*Fibonacci(4n+1)*x^n +...);
T_2(x)/T_0(x) = 3*(2 - 13*x + 89*x^2 - 610*x^3 +...+ (-1)^n*Fibonacci(4n+3)*x^n +...).
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{a(n)=polcoeff(exp(sum(m=1,n,valuation(3*m,3)*3^valuation(3*m,3)*x^m/m)+x*O(x^n)),n)}
Original entry on oeis.org
0, 0, 1, 1, 4, 5, 8, 9, 17, 21, 28, 33, 45, 53, 66, 75, 100, 117, 140, 161, 193, 221, 258, 291, 344, 389, 446, 499, 573, 639, 722, 797, 913, 1013, 1132, 1249, 1393, 1533, 1698, 1859, 2060, 2253, 2478, 2699, 2965, 3223, 3522, 3813, 4173, 4517, 4910, 5299, 5753
Offset: 0
- G. E. Andrews, A. S. Fraenkel, and J. A. Sellers, Characterizing the number of m-ary partitions modulo m, The American Mathematical Monthly, Vol. 122, No. 9 (November 2015), pp. 880-885.
- G. E. Andrews, A. S. Fraenkel, and J. A. Sellers, Characterizing the number of m-ary partitions modulo m.
- Tom Edgar, The distribution of the number of parts of m-ary partitions modulo m., arXiv:1603.00085 [math.CO], 2016.
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b[0] = 1; b[n_] := b[n] = b[Floor[n/2]] + b[n - 1];
c[n_] := Sum[Mod[Binomial[n, k], 2], {k, 0, n}];
a[n_] := (b[n] - c[n])/2;
Table[a[n], {n, 0, 52}] (* Jean-François Alcover, Dec 12 2018 *)
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def b(n):
A=[1]
for i in [1..n]:
A.append(A[i-1] + A[floor(i/2)])
return A[n]
[(b(n)-prod(x+1 for x in n.digits(2)))/2 for n in [0..60]]
A294298
Sum of products of terms in all partitions of 3*n into powers of 3.
Original entry on oeis.org
1, 4, 13, 49, 157, 481, 1534, 4693, 14170, 43357, 130918, 393601, 1188454, 3573013, 10726690, 32248957, 96815758, 290516161, 872169223, 2617128409, 7852005967, 23561605318, 70690403371, 212076797530, 636280680100, 1908892327810, 5726727270940, 17180634420931
Offset: 0
n | partitions of 3*n into powers of 3 | a(n)
----------------------------------------------------------------------------------
1 | 3 , 1+1+1 | 3+1 = 4.
2 | 3+3, 3+1+1+1, 1+1+1+1+1+1 | 9+3+1 = 13.
3 | 9 , 3+3+3 , 3+3+1+1+1 , 3+1+1+1+1+1+1, 1+1+1+1+1+1+1+1+1 | 9+27+9+3+1 = 49.
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b:= proc(n, i, p) option remember; `if`(n=0, p,
`if`(i<1, 0, add(b(n-j*i, i/3, p*i^j), j=0..n/i)))
end:
a:= n-> (t-> b(t, 3^ilog[3](t), 1))(3*n):
seq(a(n), n=0..33); # Alois P. Heinz, Oct 27 2017
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b[n_, i_, p_] := b[n, i, p] = If[n == 0, p, If[i < 1, 0, Sum[b[n - j i, i/3, p i^j], {j, 0, n/i}]]];
a[n_] := b[3n, 3^Floor@Log[3, 3n], 1];
a /@ Range[0, 33] (* Jean-François Alcover, Nov 23 2020, after Alois P. Heinz *)
A089688
Table T(n,k), n>=0 and k>=1, read by antidiagonals; the k-th row is defined by : partitions of k*n into powers of k (with T(0,k) = 1).
Original entry on oeis.org
1, 1, 1, 1, 2, 1, 1, 4, 2, 1, 1, 6, 3, 2, 1, 1, 10, 5, 3, 2, 1, 1, 14, 7, 4, 3, 2, 1, 1, 20, 9, 6, 4, 3, 2, 1, 1, 26, 12, 8, 5, 4, 3, 2, 1, 1, 36, 15, 10, 7, 5, 4, 3, 2, 1, 1, 46, 18, 12, 9, 6, 5, 4, 3, 2, 1, 1, 60, 23, 15, 11, 8, 6, 5, 4, 3, 2, 1
Offset: 0
Row k = 1 : 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... (see A000012).
Row k = 2 : 1, 2, 4, 6, 10, 14, 20, 26, 36, 46, 60, 74, ... (see A000123).
Row k = 3 : 1, 2, 3, 5, 7, 9, 12, 15, 18, 23, 28, 33, ... (see A005704).
Row k = 4 : 1, 2, 3, 4, 6, 8, 10, 12, 15, 18, 21, 24, ... (see A005705).
Row k = 5 : 1, 2, 3, 4, 5, 7, 9, 11, 13, 15, 18, 21, ... (see A005706).
A306727
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals: A(n,k) is the number of partitions of 3*n into powers of 3 less than or equal to 3^k.
Original entry on oeis.org
1, 1, 1, 1, 2, 1, 1, 2, 3, 1, 1, 2, 3, 4, 1, 1, 2, 3, 5, 5, 1, 1, 2, 3, 5, 7, 6, 1, 1, 2, 3, 5, 7, 9, 7, 1, 1, 2, 3, 5, 7, 9, 12, 8, 1, 1, 2, 3, 5, 7, 9, 12, 15, 9, 1, 1, 2, 3, 5, 7, 9, 12, 15, 18, 10, 1, 1, 2, 3, 5, 7, 9, 12, 15, 18, 22, 11, 1, 1, 2, 3, 5, 7, 9, 12, 15, 18, 23, 26, 12, 1
Offset: 0
A(3,3) = 5, because there are 5 partitions of 3*3=9 into powers of 3 less than or equal to 3^3=9: [9], [3,3,3], [3,3,1,1,1], [3,1,1,1,1,1,1], [1,1,1,1,1,1,1,1,1].
Square array A(n,k) begins:
1, 1, 1, 1, 1, 1, ...
1, 2, 2, 2, 2, 2, ...
1, 3, 3, 3, 3, 3, ...
1, 4, 5, 5, 5, 5, ...
1, 5, 7, 7, 7, 7, ...
1, 6, 9, 9, 9, 9, ...
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nmax = 12;
f[k_] := f[k] = 1/(1-x) 1/Product[1-x^(3^j), {j, 0, k-1}] + O[x]^(nmax+1) // CoefficientList[#, x]&;
A[n_, k_] := f[k][[n+1]];
Table[A[n-k, k], {n, 0, nmax}, {k, n, 0, -1}] // Flatten (* Jean-François Alcover, Nov 20 2019 *)
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def aseq(p, x, k):
# generic algorithm for any p - power base, p=3 for this sequence
if x < 0:
return 0
if x < p:
return 1
# coefficients
arr = [0]*(x+1)
arr[0] = 1
m = p**k
while m > 0:
for i in range(m, x+1, m):
arr[i] += arr[i-m]
m //= p
return arr[x]
def A(n, k):
p = 3
return aseq(p, p*n, k)
# A(n, k), 5 = A(3, 3) = aseq(3, 3*3, 3)
# Serguei Zolotov, Mar 13 2019
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