A290090 -id:A290090 - cp's OEIS frontend

A292257 a(n) is the total number of 1's in binary expansion of all proper divisors of n.

0, 1, 1, 2, 1, 4, 1, 3, 3, 4, 1, 7, 1, 5, 5, 4, 1, 8, 1, 7, 6, 5, 1, 10, 3, 5, 5, 9, 1, 14, 1, 5, 6, 4, 6, 13, 1, 5, 6, 10, 1, 15, 1, 9, 11, 6, 1, 13, 4, 9, 5, 9, 1, 14, 6, 13, 6, 6, 1, 23, 1, 7, 11, 6, 6, 14, 1, 7, 7, 15, 1, 18, 1, 5, 12, 9, 7, 16, 1, 13, 9, 5, 1, 24, 5, 6, 7, 13, 1, 26, 7, 11, 8, 7, 6, 16, 1, 11, 10, 15, 1, 14, 1, 13, 18

Offset: 1

Antti Karttunen, Oct 04 2017

If a(n) == A000120(n), then n is in A175522, if a(n) < A000120(n), then n is in A175524, and if a(n) > A000120(n), then n is in A175526.

Antti Karttunen, Table of n, a(n) for n = 1..16384
Index entries for sequences related to binary expansion of n.

Cf. A000120, A093653, A175522, A175524, A175526, A192895, A290090, A293214.

a[n_] := DivisorSum[n, DigitCount[#, 2, 1] &, # < n &]; Array[a, 100] (* Amiram Eldar, Jul 20 2023 *)
Table[Total[Flatten[IntegerDigits[#,2]&/@Most[Divisors[n]]]],{n,120}] (* Harvey P. Dale, Oct 11 2024 *)

PARI
```
A292257(n) = sumdiv(n,d,(d
				
```

a(n) = Sum_{d|n, dA000120(d).
a(n) = A093653(n) - A000120(n).
a(n) = A192895(n) + A000120(n).
a(n) = A001222(A293214(n)).
A000035(a(n)) = A000035(A290090(n)). [Parity-wise equivalent with A290090.]

A293231 a(n) = Product_{d|n, dA019565(A193231(d)).

Original entry on oeis.org

1, 2, 2, 12, 2, 36, 2, 120, 6, 60, 2, 5400, 2, 360, 30, 25200, 2, 56700, 2, 21000, 180, 840, 2, 23814000, 10, 504, 630, 50400, 2, 661500, 2, 554400, 420, 132, 300, 392931000, 2, 792, 252, 242550000, 2, 24948000, 2, 2772000, 22050, 1980, 2, 605113740000, 60, 4851000, 66, 3880800, 2, 720373500, 700, 4889808000, 396, 2772, 2, 588305025000, 2, 1848

Offset: 1

Antti Karttunen, Oct 03 2017

Antti Karttunen, Table of n, a(n) for n = 1..1024
Index entries for sequences related to binary expansion of n

Cf. A019565, A193231, A290090, A293214, A293232 (rgs-version of this sequence).

Cf. also A001317, A045544, A053576.

A019565(n) = {my(j,v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler
A193231(n) = { my(x='x); subst(lift(Mod(1, 2)*subst(Pol(binary(n), x), x, 1+x)), x, 2) }; \\ This function from Franklin T. Adams-Watters
A293231(n) = { my(m=1); fordiv(n,d,if(d < n,m *= A019565(A193231(d)))); m; };

a(n) = Product_{d|n, dA019565(A193231(d)).
For all n >= 1, A007814(a(n)) = A290090(n).
For n = 0..5, a(A001317((2^n)-1)) = A002110((2^n)-1).

A293232 Restricted growth sequence transform of A293231, where A293231(n) = Product_{d|n, dA019565(A193231(d)).

Original entry on oeis.org

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

Offset: 1

Antti Karttunen, Oct 03 2017

nonn

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

Cf. A019565, A193231.
Cf. A290090.
Differs from related A293215 for the first time at n=55, where a(55) = 39, while A293215(55) = 28.

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; };
write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }
A019565(n) = {my(j,v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler
A193231(n) = { my(x='x); subst(lift(Mod(1, 2)*subst(Pol(binary(n), x), x, 1+x)), x, 2) }; \\ This function from Franklin T. Adams-Watters
A293231(n) = { my(m=1); fordiv(n,d,if(d < n,m *= A019565(A193231(d)))); m; };
write_to_bfile(1,rgs_transform(vector(65537,n,A293231(n))),"b293232.txt");

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A292257 a(n) is the total number of 1's in binary expansion of all proper divisors of n.

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A293231 a(n) = Product_{d|n, dA019565(A193231(d)).

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A293232 Restricted growth sequence transform of A293231, where A293231(n) = Product_{d|n, dA019565(A193231(d)).

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