A071330 -id:A071330 - cp's OEIS frontend

A282062 Expansion of (x + Sum_{p prime, k>=1} x^(p^k))^2.

0, 0, 1, 2, 3, 4, 5, 4, 5, 6, 7, 6, 8, 6, 7, 6, 7, 6, 9, 6, 10, 8, 7, 4, 10, 6, 9, 8, 10, 6, 12, 6, 13, 10, 13, 8, 14, 4, 11, 8, 12, 6, 12, 6, 12, 10, 11, 4, 16, 6, 15, 8, 12, 4, 17, 6, 14, 8, 11, 4, 16, 6, 13, 8, 13, 6, 18, 4, 16, 10, 14, 4, 20, 6, 15, 12, 14, 6, 18, 4, 18, 8, 13, 8, 22, 6, 17, 8, 14, 6, 24, 8, 16, 6, 13, 4

Offset: 0

Ilya Gutkovskiy, Feb 05 2017

Number of ways to write n as an ordered sum of two prime powers (1 included).

			a(8) = 5 because we have  [7, 1], [5, 3], [4, 4], [3, 5] and [1, 7].

Robert Israel, Table of n, a(n) for n = 0..10000
Ilya Gutkovskiy, Extended graphical example
Eric Weisstein's World of Mathematics, Prime Power

Cf. A000961, A071330, A071331, A073610, A095840, A280242, A282064.

N:= 100: # to get a(0)..a(N)
P:= select(isprime, [$2..N]):
g:= x + add(add(x^(p^k),k=1..floor(log[p](N))),p=P):
S:= series(g^2,x,N+1):
seq(coeff(S,x,n),n=0..N); # Robert Israel, Feb 10 2017

nmax = 95; CoefficientList[Series[(x + Sum[Floor[1/PrimeNu[k]] x^k, {k, 2, nmax}])^2, {x, 0, nmax}], x]

G.f.: (x + Sum_{p prime, k>=1} x^(p^k))^2.

A071331 Numbers having no decomposition into a sum of two prime powers.

Original entry on oeis.org

1, 149, 331, 373, 509, 701, 757, 809, 877, 907, 959, 997, 1019, 1087, 1199, 1207, 1211, 1243, 1259, 1271, 1477, 1529, 1541, 1549, 1589, 1597, 1619, 1657, 1719, 1759, 1777, 1783, 1807, 1829, 1859, 1867, 1927, 1969, 1973, 2171, 2231

Offset: 1

Reinhard Zumkeller, May 19 2002

Luca & Stanica show that this sequence contains infinitely many Fibonacci numbers. In particular, there is some N such that for all n > N, Fibonacci(1807873 + 3543120*n) is in this sequence. - Charles R Greathouse IV, Jul 06 2011

Chen shows that there are five consecutive odd numbers M-8, M-6, M-4, M-2, M, for which all are members of the sequence. Such M may be large; Chen shows that it is less than 2^(2^253000). In fact, there exists an arithmetic progression of such M, and thus they have positive density. - Charles R Greathouse IV, Jul 06 2011

T. D. Noe, Table of n, a(n) for n = 1..1000
Florian Luca and Pantelimon Stănică, Fibonacci numbers that are not sums of two prime powers, Proceedings of the American Mathematical Society 133 (2005), pp. 1887-1890.
Yong-Gao Chen, Five consecutive positive odd numbers, none of which can be expressed as a sum of two prime powers, Mathematics of Computation 74 (2005), pp. 1025-1031.

A071330(a(n))=0. Cf. A000961, A109829, A014092.

a071331 n = a071331_list !! (n-1)
a071331_list = filter ((== 0) . a071330) [1..]
-- Reinhard Zumkeller, Jan 11 2013

primePowerQ[n_] := Length[FactorInteger[n]] == 1; decomposableQ[n_] := (r = False; Do[If[primePowerQ[k] && primePowerQ[n - k], r = True; Break[]], {k, 1, Floor[n/2]}]; r); Select[Range[3000], !decomposableQ[#]& ] (* Jean-François Alcover, Jun 13 2012 *)
Join[{1},Select[Range[4,2300],Count[IntegerPartitions[#,{2}],?( AllTrue[ #,PrimePowerQ]&)]==0&]] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale, May 28 2021 *)

isprimepower(n)=ispower(n,,&n);isprime(n)||n==1;
isA071331(n)=forprime(p=2,n\2,if(isprimepower(n-p),return(0)));forprime(p=2,sqrtint(n\2),for(e=1,log(n\2)\log(p),if(isprimepower(n-p^e),return(0))));!isprimepower(n-1)
\\ Charles R Greathouse IV, Jul 06 2011

A341123 Number of partitions of n into 5 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 9, 11, 15, 17, 23, 25, 32, 34, 42, 45, 55, 56, 68, 71, 83, 84, 100, 100, 117, 118, 136, 135, 158, 153, 179, 178, 204, 200, 234, 226, 261, 255, 291, 283, 327, 310, 357, 344, 390, 371, 430, 405, 466, 444, 505, 476, 550, 511, 589, 557, 634, 589, 684, 629

Offset: 5

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341122, A341124, A341125, A341126, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 5):
seq(a(n), n=5..64);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 5];
Table[a[n], {n, 5, 64}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

A341122 Number of partitions of n into 4 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 5, 8, 9, 12, 13, 17, 17, 22, 22, 26, 27, 33, 31, 39, 38, 44, 43, 51, 47, 58, 54, 63, 60, 71, 64, 79, 74, 88, 82, 99, 88, 108, 97, 116, 105, 126, 110, 134, 119, 141, 126, 153, 133, 164, 143, 172, 149, 184, 155, 194, 168, 204, 173, 215, 180, 227, 192, 238

Offset: 4

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341123, A341124, A341125, A341126, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 4):
seq(a(n), n=4..66);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 4];
Table[a[n], {n, 4, 66}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

A341124 Number of partitions of n into 6 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 10, 12, 17, 20, 27, 31, 41, 45, 56, 63, 77, 83, 101, 108, 128, 136, 160, 168, 196, 204, 236, 245, 281, 288, 331, 340, 387, 395, 450, 457, 519, 525, 594, 598, 677, 678, 763, 764, 855, 851, 957, 949, 1062, 1053, 1177, 1161, 1300, 1276, 1425, 1403, 1564

Offset: 6

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341122, A341123, A341125, A341126, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 6):
seq(a(n), n=6..62);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 6];
Table[a[n], {n, 6, 62}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

A341132 Number of partitions of n into 2 distinct prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 3, 3, 3, 3, 3, 4, 3, 5, 4, 3, 2, 5, 3, 4, 4, 5, 3, 6, 3, 6, 5, 6, 4, 7, 2, 5, 4, 6, 3, 6, 3, 6, 5, 5, 2, 8, 3, 7, 4, 6, 2, 8, 3, 7, 4, 5, 2, 8, 3, 6, 4, 6, 3, 9, 2, 8, 5, 7, 2, 10, 3, 7, 6, 7, 3, 9, 2, 9, 4, 6, 4, 11, 3, 8, 4, 7, 3, 12

Offset: 3

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A282062, A306433, A307726, A341140, A341141, A341142, A341143, A341144, A341145.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i-1), t-1), 0)))
    end:
a:= n-> b(n$2, 2):
seq(a(n), n=3..90);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = PrimeNu[n] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i - 1], t - 1], 0]]];
a[n_] := b[n, n, 2];
Table[a[n], {n, 3, 90}] (* Jean-François Alcover, Jul 13 2021, after Alois P. Heinz *)

A341112 Number of partitions of n into 3 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 4, 4, 6, 6, 8, 8, 10, 9, 12, 10, 13, 12, 15, 13, 17, 15, 18, 15, 19, 16, 21, 17, 23, 18, 24, 19, 27, 23, 30, 24, 32, 25, 32, 26, 34, 26, 36, 26, 36, 28, 38, 28, 40, 30, 42, 32, 43, 30, 45, 32, 47, 35, 49, 30, 50, 35, 51, 36, 53, 35, 55, 37, 54, 40, 57, 36, 61, 40, 61

Offset: 3

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A282064, A307727, A307825, A341122, A341123, A341124, A341125, A341126, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 3):
seq(a(n), n=3..75);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 3];
Table[a[n], {n, 3, 75}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

A341125 Number of partitions of n into 7 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 10, 13, 18, 22, 30, 35, 47, 54, 68, 78, 97, 107, 132, 146, 173, 190, 225, 242, 285, 305, 352, 377, 434, 456, 525, 553, 627, 659, 748, 778, 881, 916, 1028, 1068, 1197, 1232, 1381, 1421, 1578, 1619, 1801, 1837, 2041, 2079, 2296, 2337, 2583, 2613

Offset: 7

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341122, A341123, A341124, A341126, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 7):
seq(a(n), n=7..60);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 7];
Table[a[n], {n, 7, 60}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

A341126 Number of partitions of n into 8 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 10, 13, 19, 23, 32, 38, 51, 60, 77, 90, 113, 128, 158, 179, 215, 240, 287, 316, 373, 409, 475, 517, 599, 645, 741, 799, 908, 971, 1104, 1173, 1326, 1408, 1580, 1670, 1874, 1967, 2198, 2310, 2563, 2680, 2976, 3097, 3426, 3566, 3926, 4070, 4485

Offset: 8

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341122, A341123, A341124, A341125, A341127.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 8):
seq(a(n), n=8..60);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 8];
Table[a[n], {n, 8, 60}] (* Jean-François Alcover, Feb 22 2022, after _Alois P. Heinz *)

A341127 Number of partitions of n into 9 prime powers (including 1).

Original entry on oeis.org

1, 1, 2, 3, 5, 6, 10, 13, 19, 24, 33, 40, 54, 64, 83, 99, 125, 144, 180, 206, 250, 284, 341, 383, 455, 506, 593, 656, 762, 835, 965, 1054, 1206, 1309, 1491, 1610, 1825, 1964, 2213, 2374, 2664, 2843, 3179, 3387, 3769, 3998, 4440, 4695, 5194, 5480, 6043, 6357

Offset: 9

Ilya Gutkovskiy, Feb 05 2021

nonn

Cf. A000961, A010055, A071330, A341112, A341122, A341123, A341124, A341125, A341126.

q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, i, t) option remember; `if`(n=0,
      `if`(t=0, 1, 0), `if`(i<1 or t<1, 0, b(n, i-1, t)+
      `if`(q(i), b(n-i, min(n-i, i), t-1), 0)))
    end:
a:= n-> b(n$2, 9):
seq(a(n), n=9..60);  # Alois P. Heinz, Feb 05 2021

q[n_] := q[n] = Length[FactorInteger[n]] < 2;
b[n_, i_, t_] := b[n, i, t] = If[n == 0,
     If[t == 0, 1, 0], If[i < 1 || t < 1, 0, b[n, i - 1, t] +
     If[q[i], b[n - i, Min[n - i, i], t - 1], 0]]];
a[n_] := b[n, n, 9];
Table[a[n], {n, 9, 60}] (* Jean-François Alcover, Feb 22 2022, after Alois P. Heinz *)

cp's OEIS Frontend

A282062 Expansion of (x + Sum_{p prime, k>=1} x^(p^k))^2.

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A071331 Numbers having no decomposition into a sum of two prime powers.

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A341123 Number of partitions of n into 5 prime powers (including 1).

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A341122 Number of partitions of n into 4 prime powers (including 1).

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A341124 Number of partitions of n into 6 prime powers (including 1).

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A341132 Number of partitions of n into 2 distinct prime powers (including 1).

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A341112 Number of partitions of n into 3 prime powers (including 1).

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A341125 Number of partitions of n into 7 prime powers (including 1).

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A341126 Number of partitions of n into 8 prime powers (including 1).

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