A352038 Sum of the 10th powers of the odd proper divisors of n.
0, 1, 1, 1, 1, 59050, 1, 1, 59050, 9765626, 1, 59050, 1, 282475250, 9824675, 1, 1, 3486843451, 1, 9765626, 282534299, 25937424602, 1, 59050, 9765626, 137858491850, 3486843451, 282475250, 1, 576660215300, 1, 1, 25937483651, 2015993900450, 292240875, 3486843451
Offset: 1
Examples
a(10) = 9765626; a(10) = Sum_{d|10, d<10, d odd} d^10 = 1^10 + 5^10 = 9765626.
Links
Crossrefs
Programs
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Mathematica
f[2, e_] := 1; f[p_, e_] := (p^(10*e+10) - 1)/(p^10 - 1); a[1] = 0; a[n_] := Times @@ f @@@ FactorInteger[n] - If[OddQ[n], n^10, 0]; Array[a, 60] (* Amiram Eldar, Oct 11 2023 *)
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Python
from math import prod from sympy import factorint def A352038(n): return prod((p**(10*(e+1))-1)//(p**10-1) for p, e in factorint(n).items() if p > 2) - (n**10 if n % 2 else 0) # Chai Wah Wu, Mar 01 2022
Formula
a(n) = Sum_{d|n, d
G.f.: Sum_{k>=1} (2*k-1)^10 * x^(4*k-2) / (1 - x^(2*k-1)). - Ilya Gutkovskiy, Mar 02 2022
From Amiram Eldar, Oct 11 2023: (Start)
Sum_{k=1..n} a(k) ~ c * n^11, where c = (zeta(11)-1)/22 = 0.0000224631... . (End)
A352047 Sum of the divisor complements of the odd proper divisors of n.
0, 2, 3, 4, 5, 8, 7, 8, 12, 12, 11, 16, 13, 16, 23, 16, 17, 26, 19, 24, 31, 24, 23, 32, 30, 28, 39, 32, 29, 48, 31, 32, 47, 36, 47, 52, 37, 40, 55, 48, 41, 64, 43, 48, 77, 48, 47, 64, 56, 62, 71, 56, 53, 80, 71, 64, 79, 60, 59, 96, 61, 64, 103, 64, 83, 96, 67, 72, 95, 96, 71, 104
Offset: 1
Examples
a(10) = 12; a(10) = 10 * Sum_{d|10, d<10, d odd} 1 / d = 10 * (1/1 + 1/5) = 12.
Links
- Michael De Vlieger, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
A352047 := proc(n) local a,d ; a := 0 ; for d in numtheory[divisors](n) do if type(d,'odd') and d < n then a := a+n/d ; end if; end do: a ; end proc: seq(A352047(n),n=1..30) ; # R. J. Mathar, Mar 09 2022
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Mathematica
Table[n DivisorSum[n, 1/# &, # < n && OddQ[#] &], {n, 72}] (* Michael De Vlieger, Mar 02 2022 *) a[n_] := DivisorSigma[-1, n / 2^IntegerExponent[n, 2]] * n - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *)
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PARI
a(n) = n*sumdiv(n, d, if ((d%2) && (d
Michel Marcus, Mar 02 2022 -
PARI
a(n) = n * sigma(n >> valuation(n, 2), -1) - n % 2; \\ Amiram Eldar, Oct 13 2023
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Python
from math import prod from sympy import factorint def A352047(n): return prod(p**e if p == 2 else (p**(e+1)-1)//(p-1) for p, e in factorint(n).items()) - n % 2 # Chai Wah Wu, Mar 02 2022
Formula
a(n) = n * Sum_{d|n, d
a(2n+1) = A000593(2n+1) - 1. - Chai Wah Wu, Mar 01 2022
G.f.: Sum_{k>=2} k * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 14 2023
exp( 2*Sum_{n>=1} a(n)*x^n/n ) is the g.f. of A300415. - Paul D. Hanna, May 15 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^2 / 2, where c = Pi^2/8 = 1.23370055... (A111003). (End)
A352048 Sum of the squares of the divisor complements of the odd proper divisors of n.
0, 4, 9, 16, 25, 40, 49, 64, 90, 104, 121, 160, 169, 200, 259, 256, 289, 364, 361, 416, 499, 488, 529, 640, 650, 680, 819, 800, 841, 1040, 961, 1024, 1219, 1160, 1299, 1456, 1369, 1448, 1699, 1664, 1681, 2000, 1849, 1952, 2365, 2120, 2209, 2560, 2450, 2604, 2899, 2720
Offset: 1
Examples
a(10) = 10^2 * Sum_{d|10, d<10, d odd} 1 / d^2 = 10^2 * (1/1^2 + 1/5^2) = 104.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
Maple
f:= proc(n) local m,d; m:= n/2^padic:-ordp(n,2); add((n/d)^2, d = select(`<`,numtheory:-divisors(m),n)) end proc: map(f, [$1..60]); # Robert Israel, Apr 03 2023
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Mathematica
a[n_] := n^2 DivisorSum[n, If[# < n && OddQ[#], 1/#^2, 0]&]; Table[a[n], {n, 1, 60}] (* Jean-François Alcover, May 11 2023 *) a[n_] := DivisorSigma[-2, n/2^IntegerExponent[n, 2]] * n^2 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *)
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PARI
a(n) = n^2*sumdiv(n, d, if ((d
Michel Marcus, May 11 2023 -
PARI
a(n) = n^2 * sigma(n >> valuation(n, 2), -2) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^2 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^2 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 14 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^3 / 3, where c = 7*zeta(3)/8 = 1.0517997... (A233091). (End)
A352049 Sum of the cubes of the divisor complements of the odd proper divisors of n.
0, 8, 27, 64, 125, 224, 343, 512, 756, 1008, 1331, 1792, 2197, 2752, 3527, 4096, 4913, 6056, 6859, 8064, 9631, 10656, 12167, 14336, 15750, 17584, 20439, 22016, 24389, 28224, 29791, 32768, 37295, 39312, 43343, 48448, 50653, 54880, 61543, 64512, 68921, 77056, 79507
Offset: 1
Examples
a(10) = 10^3 * Sum_{d|10, d<10, d odd} 1 / d^3 = 10^3 * (1/1^3 + 1/5^3) = 1008.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
f:= proc(n) local m,d; m:= n/2^padic:-ordp(n,2); add((n/d)^3, d = select(`<`,numtheory:-divisors(m),n)) end proc: map(f, [$1..50]); # Robert Israel, Apr 03 2023
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Mathematica
A352049[n_]:=DivisorSum[n,1/#^3&,#
A352049,50] (* Paolo Xausa, Aug 09 2023 *) a[n_] := DivisorSigma[-3, n/2^IntegerExponent[n, 2]] * n^3 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^3 * sigma(n >> valuation(n, 2), -3) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^3 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^3 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 14 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^4 / 4, where c = 15*zeta(4)/16 = 1.01467803... (A300707). (End)
A352050 Sum of the 4th powers of the divisor complements of the odd proper divisors of n.
0, 16, 81, 256, 625, 1312, 2401, 4096, 6642, 10016, 14641, 20992, 28561, 38432, 51331, 65536, 83521, 106288, 130321, 160256, 196963, 234272, 279841, 335872, 391250, 456992, 538083, 614912, 707281, 821312, 923521, 1048576, 1200643, 1336352, 1503651, 1700608, 1874161
Offset: 1
Examples
a(10) = 10^4 * Sum_{d|10, d<10, d odd} 1 / d^4 = 10^4 * (1/1^4 + 1/5^4) = 10016.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
f:= proc(n) local m,d; m:= n/2^padic:-ordp(n,2); add((n/d)^4, d = select(`<`,numtheory:-divisors(m),n)) end proc:map(f, [$1..40]); # Robert Israel, Apr 03 2023
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Mathematica
A352050[n_]:=DivisorSum[n,1/#^4&,#
A352050,50] (* Paolo Xausa, Aug 09 2023 *) a[n_] := DivisorSigma[-4, n/2^IntegerExponent[n, 2]] * n^4 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^4 * sigma(n >> valuation(n, 2), -4) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^4 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^4 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 14 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^5 / 5, where c = 31*zeta(5)/32 = 1.00452376... . (End)
A352051 Sum of the 5th powers of the divisor complements of the odd proper divisors of n.
0, 32, 243, 1024, 3125, 7808, 16807, 32768, 59292, 100032, 161051, 249856, 371293, 537856, 762743, 1048576, 1419857, 1897376, 2476099, 3201024, 4101151, 5153664, 6436343, 7995392, 9768750, 11881408, 14408199, 17211392, 20511149, 24407808, 28629151, 33554432, 39296687
Offset: 1
Examples
a(10) = 10^5 * Sum_{d|10, d<10, d odd} 1 / d^5 = 10^5 * (1/1^5 + 1/5^5) = 100032.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Maple
f:= proc(n) local m,d; m:= n/2^padic:-ordp(n,2); add((n/d)^5, d = select(`<`,numtheory:-divisors(m),n)) end proc: map(f, [$1..40]); # Robert Israel, Apr 03 2023
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Mathematica
A352051[n_]:=DivisorSum[n,1/#^5&,#
A352051,50] (* Paolo Xausa, Aug 09 2023 *) a[n_] := DivisorSigma[-5, n/2^IntegerExponent[n, 2]] * n^5 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^5 * sigma(n >> valuation(n, 2), -5) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^5 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^5 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 18 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^6 / 6, where c = 63*zeta(6)/64 = 1.00144707... . (End)
A352052 Sum of the 6th powers of the divisor complements of the odd proper divisors of n.
0, 64, 729, 4096, 15625, 46720, 117649, 262144, 532170, 1000064, 1771561, 2990080, 4826809, 7529600, 11406979, 16777216, 24137569, 34058944, 47045881, 64004096, 85884499, 113379968, 148035889, 191365120, 244156250, 308915840, 387952659, 481894400, 594823321
Offset: 1
Examples
a(10) = 10^6 * Sum_{d|10, d<10, d odd} 1 / d^6 = 10^6 * (1/1^6 + 1/5^6) = 1000064.
Links
- Robert Israel, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
Maple
f:= proc(n) local m,d; m:= n/2^padic:-ordp(n,2); add((n/d)^6, d = select(`<`,numtheory:-divisors(m),n)) end proc: map(f, [$1..30]); # Robert Israel, Apr 03 2023
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Mathematica
Table[n^6*DivisorSum[n, 1/#^6 &, And[# < n, OddQ[#]] &], {n, 29}] (* Michael De Vlieger, Apr 04 2023 *) a[n_] := DivisorSigma[-6, n/2^IntegerExponent[n, 2]] * n^6 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *)
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PARI
a(n) = n^6*sumdiv(n, d, if ((d
Michel Marcus, Apr 04 2023 -
PARI
a(n) = n^6 * sigma(n >> valuation(n, 2), -6) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^6 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^6 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 18 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^7 / 7, where c = 127*zeta(7)/128 = 1.000471548... . (End)
A352053 Sum of the 7th powers of the divisor complements of the odd proper divisors of n.
0, 128, 2187, 16384, 78125, 280064, 823543, 2097152, 4785156, 10000128, 19487171, 35848192, 62748517, 105413632, 170939687, 268435456, 410338673, 612500096, 893871739, 1280016384, 1801914271, 2494358016, 3404825447, 4588568576, 6103593750, 8031810304, 10465138359
Offset: 1
Examples
a(10) = 10^7 * Sum_{d|10, d<10, d odd} 1/d^7 = 10^7 * (1/1^7 + 1/5^7) = 10000128.
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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Mathematica
A352053[n_]:=DivisorSum[n,1/#^7&,#
A352053,50] (* Paolo Xausa, Aug 09 2023 *) a[n_] := DivisorSigma[-7, n/2^IntegerExponent[n, 2]] * n^7 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^7 * sigma(n >> valuation(n, 2), -7) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^7 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^7 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 18 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^8 / 8, where c = 255*zeta(8)/256 = 1.000155179... . (End)
A352054 Sum of the 8th powers of the divisor complements of the odd proper divisors of n.
0, 256, 6561, 65536, 390625, 1679872, 5764801, 16777216, 43053282, 100000256, 214358881, 430047232, 815730721, 1475789312, 2563287811, 4294967296, 6975757441, 11021640448, 16983563041, 25600065536, 37828630723, 54875873792, 78310985281, 110092091392, 152588281250
Offset: 1
Examples
a(10) = 10^8 * Sum_{d|10, d<10, d odd} 1 / d^8 = 10^8 * (1/1^8 + 1/5^8) = 100000256.
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
Mathematica
A352054[n_]:=DivisorSum[n,1/#^8&,#
A352054,50] (* Paolo Xausa, Aug 09 2023 *) a[n_] := DivisorSigma[-8, n/2^IntegerExponent[n, 2]] * n^8 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^8 * sigma(n >> valuation(n, 2), -8) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^8 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^8 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 19 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^9 / 9, where c = 511*zeta(9)/512 = 1.0000513451... . (End)
A352055 Sum of the 9th powers of the divisor complements of the odd proper divisors of n.
0, 512, 19683, 262144, 1953125, 10078208, 40353607, 134217728, 387440172, 1000000512, 2357947691, 5160042496, 10604499373, 20661047296, 38445332183, 68719476736, 118587876497, 198369368576, 322687697779, 512000262144, 794320419871, 1207269218304, 1801152661463, 2641941757952
Offset: 1
Examples
a(10) = 10^9 * Sum_{d|10, d<10, d odd} 1 / d^9 = 10^9 * (1/1^9 + 1/5^9) = 1000000512.
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
-
Mathematica
A352055[n_]:=DivisorSum[n,1/#^9&,#
A352055,50] (* Paolo Xausa, Aug 10 2023 *) a[n_] := DivisorSigma[-9, n/2^IntegerExponent[n, 2]] * n^9 - Mod[n, 2]; Array[a, 100] (* Amiram Eldar, Oct 13 2023 *) -
PARI
a(n) = n^9 * sigma(n >> valuation(n, 2), -9) - n % 2; \\ Amiram Eldar, Oct 13 2023
Formula
a(n) = n^9 * Sum_{d|n, d
G.f.: Sum_{k>=2} k^9 * x^k / (1 - x^(2*k)). - Ilya Gutkovskiy, May 19 2023
From Amiram Eldar, Oct 13 2023: (Start)
Sum_{k=1..n} a(k) = c * n^10 / 10, where c = 1023*zeta(10)/1024 = 1.0000170413... . (End)