A285328 -id:A285328 - cp's OEIS frontend

A284571 Permutation of natural numbers: a(1) = 1, a(A005117(1+n)) = 2a(n), a(A065642(1+n)) = 1 + 2a(n).

1, 2, 4, 3, 8, 6, 16, 9, 5, 12, 32, 17, 18, 10, 24, 33, 64, 65, 34, 11, 36, 20, 48, 129, 7, 66, 19, 37, 128, 130, 68, 49, 22, 72, 40, 97, 96, 258, 14, 69, 132, 38, 74, 73, 21, 256, 260, 81, 13, 29, 136, 15, 98, 521, 44, 39, 144, 80, 194, 257, 192, 516, 23, 137, 28, 138, 264, 45, 76, 148, 146, 197, 42, 512, 147, 193, 520, 162, 26, 27

Offset: 1

Antti Karttunen, Apr 17 2017

nonn

Antti Karttunen, Table of n, a(n) for n = 1..10000
Index entries for sequences that are permutations of the natural numbers

Inverse: A284572.
Cf. A005117, A008683, A013928, A065642, A285328.
Similar or related permutations: A243343, A243345, A277695, A285111.

from operator import mul
from sympy import primefactors
from sympy.ntheory.factor_ import core
def a007947(n): return 1 if n<2 else reduce(mul, primefactors(n))
def a285328(n):
    if core(n) == n: return 1
    k=n - 1
    while k>0:
        if a007947(k) == a007947(n): return k
        else: k-=1
def a013928(n): return sum(1 for i in range(1, n) if core(i) == i)
def a(n):
    if n==1: return 1
    if core(n)==n: return 2*a(a013928(n))
    else: return 1 + 2*a(a285328(n) - 1)
[a(n) for n in range(1, 121)] # Indranil Ghosh, Apr 17 2017

a(1) = 1, for n > 1, if A008683(n) <> 0 [when n is squarefree], a(n) = 2*a(A013928(n)), otherwise a(n) = 1 + 2*a(A285328(n)-1).

A322806 Lexicographically earliest such sequence a that a(i) = a(j) => A285330(i) = A285330(j) for all i, j.

Original entry on oeis.org

1, 2, 3, 3, 4, 5, 6, 4, 5, 7, 8, 9, 10, 11, 9, 6, 12, 13, 14, 15, 15, 16, 17, 18, 7, 19, 11, 20, 21, 22, 23, 8, 18, 24, 13, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 22, 38, 39, 40, 41, 42, 29, 43, 44, 45, 46, 47, 48, 49, 50, 10, 37, 51, 52, 28, 53, 54, 55, 56, 57, 58, 59, 60, 25, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 38

Offset: 1

Antti Karttunen, Dec 26 2018

nonn

Restricted growth sequence transform of A285330.

Antti Karttunen, Table of n, a(n) for n = 1..65537

Cf. A048675, A285328, A285330, A285332, A285333, A286543, A322807.

up_to = 65537;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ From A048675
A285328(n) = { my(r); if((n > 1 && !bitand(n,(n-1))), (n/2), r=A007947(n); if(r==n,1,n = n-r; while(A007947(n) <> r, n = n-r); n)); };
A285330(n) = if(issquarefree(n),A048675(n),A285328(n));
v322806 = rgs_transform(vector(up_to,n,A285330(n)));
A322806(n) = v322806[n];

A322811 a(1) = 0; for n > 1, a(n) = A001221(A285330(n)).

Original entry on oeis.org

0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 1, 1, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 1, 1, 2, 2, 1, 1, 2, 1, 2, 3, 2, 1, 2, 2, 2, 3, 2, 1, 3, 1, 2, 2, 1, 2, 1, 1, 2, 3, 1, 1, 2, 1, 2, 2, 2, 2, 2, 1, 2, 1, 2, 1, 3, 2, 2, 2, 2, 1, 3, 2, 2, 3, 3, 3, 2, 1, 2, 2, 2, 1, 1, 1, 2, 2

Offset: 1

Antti Karttunen, Dec 27 2018

nonn

For all i, j:
  A322806(i) = A322806(j) => a(i) = a(j),
  A322807(i) = A322807(j) => a(i) = a(j).

Antti Karttunen, Table of n, a(n) for n = 1..10000

Cf. A001221, A048675, A285330, A322806, A322807, A322812.

A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ From A048675
A285328(n) = { my(r); if((n > 1 && !bitand(n,(n-1))), (n/2), r=A007947(n); if(r==n,1,n = n-r; while(A007947(n) <> r, n = n-r); n)); };
A285330(n) = if(issquarefree(n),A048675(n),A285328(n));
A322811(n) = if(1==n,0,omega(A285330(n)));

a(1) = 0; for n > 1, a(n) = A001221(A285330(n)).

If n > 1 is squarefree, a(n) = A322812(n) = A001221(A048675(n)), otherwise a(n) = A001221(A285328(n)) = A001221(n).

A322861 Lexicographically earliest such sequence a that a(i) = a(j) => A278222(A285330(i)) = A278222(A285330(j)) for all i, j.

Original entry on oeis.org

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

Offset: 1

Antti Karttunen, Dec 31 2018

nonn

Restricted growth sequence transform of A278222(A285330(n)).
For all i, j:
  A322806(i) = A322806(j) => a(i) = a(j),
  A322807(i) = A322807(j) => a(i) = a(j),
  a(i) = a(j) => A322862(i) = A322862(j).

Cf. A048675, A278222, A285330, A286622, A322806, A322807, A322862, A322868.

up_to = 65537;
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t };
A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ From A048675
A285328(n) = { my(r); if((n > 1 && !bitand(n,(n-1))), (n/2), r=A007947(n); if(r==n,1,n = n-r; while(A007947(n) <> r, n = n-r); n)); };
A285330(n) = if(moebius(n)<>0,A048675(n),A285328(n));
A278222(n) = A046523(A005940(1+n));
v322861 = rgs_transform(vector(up_to,n,A278222(A285330(n))));
A322861(n) = v322861[n];

A322862 a(n) = A000120(A285330(n)).

Original entry on oeis.org

0, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 3, 1, 3, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 1, 3, 1, 3, 4, 2, 1, 2, 3, 2, 2, 3, 1, 2, 2, 3, 2, 2, 1, 4, 1, 2, 3, 1, 2, 3, 1, 2, 2, 3, 1, 4, 1, 2, 4, 3, 2, 3, 1, 3, 4, 2, 1, 3, 2, 2, 2, 3, 1, 4, 2, 4, 2, 2, 2, 2, 1, 3, 2, 2, 1, 3, 1, 3, 3

Offset: 1

Antti Karttunen, Dec 31 2018

nonn

Antti Karttunen, Table of n, a(n) for n = 1..16384
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..65537
Index entries for sequences related to binary expansion of n
Index entries for sequences computed from indices in prime factorization

Cf. A000120, A001221, A001222, A285328, A285330, A322811, A322861, A322869.

Table[DigitCount[#, 2, 1] &@ Which[n == 1, 0, MoebiusMu@ n != 0, Total@ Map[#2*2^(PrimePi@ #1 - 1) & @@ # &, FactorInteger[n]], True, With[{r = DivisorSum[n, EulerPhi[#] Abs@ MoebiusMu[#] &]}, SelectFirst[Range[n - 2, 2, -1], DivisorSum[#, EulerPhi[#] Abs@ MoebiusMu[#] &] == r &]]], {n, 105}] (* Michael De Vlieger, Dec 31 2018 *)

A007947(n) = factorback(factorint(n)[, 1]); \\ From A007947
A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ From A048675
A285328(n) = { my(r); if((n > 1 && !bitand(n,(n-1))), (n/2), r=A007947(n); if(r==n,1,n = n-r; while(A007947(n) <> r, n = n-r); n)); };
A285330(n) = if(moebius(n)<>0,A048675(n),A285328(n));
A322862(n) = hammingweight(A285330(n));
\\ Or just as:
A322862(n) = if(issquarefree(n), omega(n), hammingweight(A285328(n)));

a(n) = A000120(A285330(n)).

If n is squarefree, a(n) = A322869(n) = A000120(A048675(n)) = A001221(n), otherwise a(n) = A000120(A285328(n)).

cp's OEIS Frontend

A284571 Permutation of natural numbers: a(1) = 1, a(A005117(1+n)) = 2*a(n), a(A065642(1+n)) = 1 + 2*a(n).

Views

Author

Keywords

Links

Crossrefs

Programs

Python

Formula

A322806 Lexicographically earliest such sequence a that a(i) = a(j) => A285330(i) = A285330(j) for all i, j.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

PARI

A322811 a(1) = 0; for n > 1, a(n) = A001221(A285330(n)).

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

PARI

Formula

A322861 Lexicographically earliest such sequence a that a(i) = a(j) => A278222(A285330(i)) = A278222(A285330(j)) for all i, j.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

PARI

A322862 a(n) = A000120(A285330(n)).

Views

Author

Keywords

Links

Crossrefs

Programs

Mathematica

PARI

Formula

A284571 Permutation of natural numbers: a(1) = 1, a(A005117(1+n)) = 2a(n), a(A065642(1+n)) = 1 + 2a(n).