A343978
Number of ordered 6-tuples (a,b,c,d,e,f) with gcd(a,b,c,d,e,f)=1 (1<= {a,b,c,d,e,f} <= n).
Original entry on oeis.org
1, 63, 727, 4031, 15559, 45863, 116855, 257983, 526615, 983583, 1755143, 2935231, 4776055, 7407727, 11256623, 16498719, 23859071, 33434063, 46467719, 62949975, 84644439, 111486599, 146142583, 187854119, 240880239, 303814503, 382049919, 473813703, 586746719
Offset: 1
- Joachim von zur Gathen and Jürgen Gerhard, Modern Computer Algebra, Cambridge University Press, Second Edition 2003, pp. 53-54.
-
a(n)={sum(k=1, n+1, moebius(k)*(n\k)^6)} \\ Andrew Howroyd, May 08 2021
-
from labmath import mobius
def A343978(n): return sum(mobius(k)*(n//k)**6 for k in range(1, n+1))
-
from functools import lru_cache
@lru_cache(maxsize=None)
def A343978(n):
if n == 0:
return 0
c, j, k1 = 1, 2, n//2
while k1 > 1:
j2 = n//k1 + 1
c += (j2-j)*A343978(k1)
j, k1 = j2, n//j2
return n*(n**5-1)-c+j # Chai Wah Wu, May 17 2021
A342586
a(n) is the number of pairs (x,y) with 1 <= x, y <= 10^n and gcd(x,y)=1.
Original entry on oeis.org
1, 63, 6087, 608383, 60794971, 6079301507, 607927104783, 60792712854483, 6079271032731815, 607927102346016827, 60792710185772432731, 6079271018566772422279, 607927101854119608051819, 60792710185405797839054887, 6079271018540289787820715707, 607927101854027018957417670303
Offset: 0
- Joachim von zur Gathen and Jürgen Gerhard, Modern Computer Algebra, Cambridge University Press, Second Edition 2003, pp. 53-54. (See link below.)
Related counts of k-tuples:
-
a342586(n)=my(s, m=10^n); forfactored(k=1,m,s+=eulerphi(k)); s*2-1 \\ Bruce Garner, Mar 29 2021
-
a342586(n)=my(s, m=10^n); forsquarefree(k=1,m,s+=moebius(k)*(m\k[1])^2); s \\ Bruce Garner, Mar 29 2021
-
import math
for n in range (0,10):
counter = 0
for x in range (1, pow(10,n)+1):
for y in range(1, pow(10,n)+1):
if math.gcd(y,x) == 1:
counter += 1
print(n, counter)
-
from functools import lru_cache
@lru_cache(maxsize=None)
def A018805(n):
if n == 1: return 1
return n*n - sum(A018805(n//j) for j in range(2, n//2+1)) - (n+1)//2
print([A018805(10**n) for n in range(8)]) # Michael S. Branicky, Mar 18 2021
A342841
Number of ordered triples (x, y, z) with gcd(x, y, z) = 1 and 1 <= {x, y, z} <= 10^n.
Original entry on oeis.org
1, 841, 832693, 832046137, 831916552903, 831908477106883, 831907430687799769, 831907383078281024371, 831907373418800027750413, 831907372722449100147414487, 831907372589073124899487831735, 831907372581823023465031521920149, 831907372580768386561159867257319711
Offset: 0
For visualization, the set(x, y, z) is inscribed in a cube matrix.
"o" stands for a gcd = 1.
"." stands for a gcd > 1.
.
For n=1, the size of the cube matrix is 10 X 10 X 10:
.
/ : : : : : : : : : :
/ 100 Sum (z = 1)
z = 7 |/1 2 3 4 5 6 7 8 9 10 |
--+--------------------- 75 Sum (z = 2)
1 /| o o o o o o o o o o 10 |
2/ | o o o o o o o o o o 10 91 Sum (z = 3)
/ 10 |
z = 8 |/1 2 3 4 5 6 7 8 9 10 10 75 Sum (z = 4)
--+--------------------- 10 /
1 /| o o o o o o o o o o 10 10 96 Sum (z = 5)
2/ | o . o . o . o . o . 5 9 /
/ 10 10 67 Sum (z = 6)
z = 9 |/1 2 3 4 5 6 7 8 9 10 5 10 /
--+--------------------- 10 10 /
1 /| o o o o o o o o o o 10 5 --/
2/ | o o o o o o o o o o 10 10 99 Sum (z = 7)
/ 7 5 /
z = 10 |/1 2 3 4 5 6 7 8 9 10 10 10 /
--+--------------------- 10 5 /
1 | o o o o o o o o o o 10 7 --/
2 | o . o . o . o . o . 5 10 75 Sum (z = 8)
3 | o o o o o o o o o o 10 10 /
4 | o . o . o . o . o . 5 7 /
5 | o o o o . o o o o . 8 10 /
6 | o . o . o . o . o . 5 --/
7 | o o o o o o o o o o 10 91 Sum (z = 9)
8 | o . o . o . o . o . 5 /
9 | o o o o o o o o o o 10 /
10 | o . o . . . o . o . 4 /
--/
72 Sum (z = 10)
/
|
------
841 Cube Sum (z = 1..10)
- Joachim von zur Gathen and Jürgen Gerhard, Modern Computer Algebra, Cambridge University Press, Second Edition 2003, pp. 53-54.
Related counts of k-tuples:
-
import math
for n in range (0, 10):
counter = 0
for x in range (1, pow(10, n)+1):
for y in range(1, pow(10, n)+1):
for z in range(1, pow(10, n)+1):
if math.gcd(math.gcd(y, x),z) == 1:
counter += 1
print(n, counter)
A343527
Number of ordered quadruples (w, x, y, z) with gcd(w, x, y, z) = 1 and 1 <= {w, x, y, z} <= 2^n.
Original entry on oeis.org
1, 15, 239, 3823, 60735, 972191, 15517679, 248252879, 3969108895, 63506982943, 1015951568815, 16255093526239, 260068569617727, 4161109496115135, 66577084386669199, 1065232436999055375, 17043668344393625999, 272698739815301095247, 4363176901343767529551, 69810828455823683068415, 1116973047989955380768527
Offset: 0
.
For n=3, the size of the gris is 8 X 8 X 8 X 8:
.
o------------x(w=8)-------------o
/|. ./ |
/ |. ./ |
/ |. ./ |
/ |. ./ |
/ |. z(w=8) |
/ |. . / |
/ |. . / |
/ |. . / y(w=8)
o------------------------------.o |
|\ /|¯¯¯¯¯¯x(w=1)¯¯¯¯¯¯/. | |
| w / | /.| | |
| \ z(w=1)| /. | | |
| \ / |y(w=1) /. | | |
| \/-------------------/. | | |
| | | | | | w | sums
| | Cube at w = 1 | | | | ----+-----
| | 8 X 8 X 8 | _ _| |---------o 1 | 512
| | contains | / | / 2 | 448
| | 512 | / | / 3 | 504
| | completely | / | / 4 | 448
| | reduced fractions | / | / 5 | 511
| | |/ | / 6 | 441
| /------------------- \ | / 7 | 511
| / \ | / 8 | 448
| w w | / ----+-----
| / \ | / sum for a(3) | 3823
| / \ |/
o -------------------------------o
A343282
Number of ordered 5-tuples (v,w, x, y, z) with gcd(v, w, x, y, z) = 1 and 1 <= {v, w, x, y, z} <= 10^n.
Original entry on oeis.org
1, 96601, 9645718621, 964407482028001, 96438925911789115351, 9643875373658964992585011, 964387358678775616636890654841, 96438734235127451288511508421855851, 9643873406165059293451290072800801506621
Offset: 0
- Joachim von zur Gathen and Jürgen Gerhard, Modern Computer Algebra, Cambridge University Press, Second Edition 2003, pp. 53-54.
Related counts of k-tuples:
A344038
Number of ordered 6-tuples (a,b,c,d,e,f) with gcd(a,b,c,d,e,f)=1 (1<= {a,b,c,d,e,f} <= 10^n).
Original entry on oeis.org
1, 983583, 983029267047, 982960635742968103, 982953384128772770413831, 982952672223441253533233827367, 982952600027678075050509511271466303, 982952593055042000417993486008754893529583, 982952592342881094406730790044111038427637071855
Offset: 0
Related counts of k-tuples:
-
a(n)={sum(k=1, 10^n+1, moebius(k)*(10^n\k)^6)} \\ Andrew Howroyd, May 08 2021
-
from labmath import mobius
def A344038(n): return sum(mobius(k)*(10**n//k)**6 for k in range(1, 10**n+1))
Showing 1-6 of 6 results.