cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A351198 Sum of the 10th powers of the primes dividing n.

Original entry on oeis.org

0, 1024, 59049, 1024, 9765625, 60073, 282475249, 1024, 59049, 9766649, 25937424601, 60073, 137858491849, 282476273, 9824674, 1024, 2015993900449, 60073, 6131066257801, 9766649, 282534298, 25937425625, 41426511213649, 60073, 9765625, 137858492873, 59049, 282476273
Offset: 1

Views

Author

Wesley Ivan Hurt, Feb 04 2022

Keywords

Comments

Inverse Möbius transform of n^10 * c(n), where c(n) is the prime characteristic (A010051). - Wesley Ivan Hurt, Jun 22 2024

Crossrefs

Sum of the k-th powers of the primes dividing n for k=0..10 : A001221 (k=0), A008472 (k=1), A005063 (k=2), A005064 (k=3), A005065 (k=4), A351193 (k=5), A351194 (k=6), A351195 (k=7), A351196 (k=8), A351197 (k=9), this sequence (k=10).
Cf. A010051, A030629 (p^10).

Programs

  • Mathematica
    Array[DivisorSum[#, #^10 &, PrimeQ] &, 50]
    f[p_, e_] := p^10; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 20 2022 *)
  • PARI
    a(n) = vecsum(apply(x->x^10, factor(n)[, 1])); \\ Michel Marcus, Feb 05 2022
  • Python
    from sympy import primefactors
    def A351198(n): return sum(p**10 for p in primefactors(n)) # Chai Wah Wu, Feb 04 2022
    

Formula

a(n) = Sum_{p|n, p prime} p^10.
G.f.: Sum_{k>=1} prime(k)^10 * x^prime(k) / (1 - x^prime(k)). - Ilya Gutkovskiy, Feb 16 2022
Additive with a(p^e) = p^10. - Amiram Eldar, Jun 20 2022
a(n) = Sum_{d|n} d^10 * c(d), where c = A010051. - Wesley Ivan Hurt, Jun 22 2024

A005079 Sum of squares of primes = 1 mod 4 dividing n.

Original entry on oeis.org

0, 0, 0, 0, 25, 0, 0, 0, 0, 25, 0, 0, 169, 0, 25, 0, 289, 0, 0, 25, 0, 0, 0, 0, 25, 169, 0, 0, 841, 25, 0, 0, 0, 289, 25, 0, 1369, 0, 169, 25, 1681, 0, 0, 0, 25, 0, 0, 0, 0, 25, 289, 169, 2809, 0, 25, 0, 0, 841, 0, 25, 3721, 0, 0, 0, 194, 0, 0, 289, 0, 25, 0, 0, 5329, 1369, 25, 0, 0, 169, 0, 25, 0, 1681, 0, 0, 314
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Array[DivisorSum[#, #^2 &, And[PrimeQ@ #, Mod[#, 4] == 1] &] &, 85] (* Michael De Vlieger, Jul 11 2017 *)
    f[p_, e_] := If[Mod[p, 4] == 1, p^2, 0]; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 21 2022 *)
  • PARI
    a(n) = my(f=factor(n)); sum(k=1, #f~, if (((p=f[k,1])%4) == 1, p^2)); \\ Michel Marcus, Jul 11 2017
  • Scheme
    (define (A005079 n) (if (= 1 n) 0 (+ (if (= 1 (modulo (A020639 n) 4)) (A000290 (A020639 n)) 0) (A005079 (A028234 n))))) ;; Antti Karttunen, Jul 11 2017
    

Formula

Additive with a(p^e) = p^2 if p = 1 (mod 4), 0 otherwise.
a(n) = A005063(n) - A005083(n) - 4*A059841(n). - Antti Karttunen, Jul 11 2017

Extensions

More terms from Antti Karttunen, Jul 11 2017

A005083 Sum of squares of primes = 3 mod 4 dividing n.

Original entry on oeis.org

0, 0, 9, 0, 0, 9, 49, 0, 9, 0, 121, 9, 0, 49, 9, 0, 0, 9, 361, 0, 58, 121, 529, 9, 0, 0, 9, 49, 0, 9, 961, 0, 130, 0, 49, 9, 0, 361, 9, 0, 0, 58, 1849, 121, 9, 529, 2209, 9, 49, 0, 9, 0, 0, 9, 121, 49, 370, 0, 3481, 9, 0, 961, 58, 0, 0, 130, 4489, 0, 538, 49, 5041, 9, 0, 0, 9, 361, 170, 9, 6241, 0, 9, 0, 6889, 58
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Array[DivisorSum[#, #^2 &, And[PrimeQ@ #, Mod[#, 4] == 3] &] &, 84] (* Michael De Vlieger, Jul 11 2017 *)
    f[p_, e_] := If[Mod[p, 4] == 3, p^2, 0]; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 21 2022 *)
  • PARI
    a(n) = my(f=factor(n)); sum(k=1, #f~, if (((p=f[k,1])%4) == 3, p^2)); \\ Michel Marcus, Jul 11 2017
  • Scheme
    (define (A005083 n) (if (= 1 n) 0 (+ (if (= 3 (modulo (A020639 n) 4)) (A000290 (A020639 n)) 0) (A005083 (A028234 n))))) ;; Antti Karttunen, Jul 11 2017
    

Formula

Additive with a(p^e) = p^2 if p = 3 (mod 4), 0 otherwise.
a(n) = A005063(n) - A005079(n) - 4*A059841(n). - Antti Karttunen, Jul 11 2017

Extensions

More terms from Antti Karttunen, Jul 11 2017

A351196 Sum of the 8th powers of the primes dividing n.

Original entry on oeis.org

0, 256, 6561, 256, 390625, 6817, 5764801, 256, 6561, 390881, 214358881, 6817, 815730721, 5765057, 397186, 256, 6975757441, 6817, 16983563041, 390881, 5771362, 214359137, 78310985281, 6817, 390625, 815730977, 6561, 5765057, 500246412961, 397442, 852891037441, 256
Offset: 1

Views

Author

Wesley Ivan Hurt, Feb 04 2022

Keywords

Comments

Inverse Möbius transform of n^8 * c(n), where c(n) is the prime characteristic (A010051). - Wesley Ivan Hurt, Jun 22 2024

Crossrefs

Sum of the k-th powers of the primes dividing n for k=0..10 : A001221 (k=0), A008472 (k=1), A005063 (k=2), A005064 (k=3), A005065 (k=4), A351193 (k=5), A351194 (k=6), A351195 (k=7), this sequence (k=8), A351197 (k=9), A351198 (k=10).
Cf. A010051.

Programs

  • Mathematica
    Array[DivisorSum[#, #^8 &, PrimeQ] &, 50]
    f[p_, e_] := p^8; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 20 2022 *)
  • Python
    from sympy import primefactors
    def A351196(n): return sum(p**8 for p in primefactors(n)) # Chai Wah Wu, Feb 05 2022

Formula

a(n) = Sum_{p|n, p prime} p^8.
G.f.: Sum_{k>=1} prime(k)^8 * x^prime(k) / (1 - x^prime(k)). - Ilya Gutkovskiy, Feb 16 2022
Additive with a(p^e) = p^8. - Amiram Eldar, Jun 20 2022
a(n) = Sum_{d|n} d^8 * c(d), where c = A010051. - Wesley Ivan Hurt, Jun 22 2024

A005066 Sum of squares of odd primes dividing n.

Original entry on oeis.org

0, 0, 9, 0, 25, 9, 49, 0, 9, 25, 121, 9, 169, 49, 34, 0, 289, 9, 361, 25, 58, 121, 529, 9, 25, 169, 9, 49, 841, 34, 961, 0, 130, 289, 74, 9, 1369, 361, 178, 25, 1681, 58, 1849, 121, 34, 529, 2209, 9, 49, 25, 298, 169, 2809, 9, 146, 49, 370, 841, 3481, 34, 3721, 961, 58, 0, 194, 130, 4489, 289, 538, 74, 5041, 9, 5329, 1369
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Total[Select[Divisors[n],OddQ[#]&&PrimeQ[#]&]^2],{n,60}] (* Harvey P. Dale, May 02 2012 *)
    Array[DivisorSum[#, #^2 &, And[PrimeQ@ #, OddQ@ #] &] &, 74] (* Michael De Vlieger, Jul 11 2017 *)
    f[2, e_] := 0; f[p_, e_] := p^2; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 20 2022 *)
  • PARI
    a(n) = sumdiv(n, d, ((d%2) && isprime(d))*d^2); \\ Michel Marcus, Jan 04 2017
    
  • Python
    from sympy import primefactors
    def a(n): return sum(p**2 for p in primefactors(n) if p % 2)
    print([a(n) for n in range(1, 101)]) # Indranil Ghosh, Jul 11 2017
  • Scheme
    (define (A005066 n) (cond ((= 1 n) 0) ((even? n) (A005066 (/ n 2))) (else (+ (A000290 (A020639 n)) (A005066 (A028234 n)))))) ;; Antti Karttunen, Jul 10 2017
    

Formula

Additive with a(p^e) = 0 if p = 2, p^2 otherwise.
G.f.: Sum_{k>=2} prime(k)^2*x^prime(k)/(1 - x^prime(k)). - Ilya Gutkovskiy, Jan 04 2017
From Antti Karttunen, Jul 10 & 11 2017: (Start)
a(1) = 0; after which, for even n: a(n) = a(n/2), for odd n: a(n) = A020639(n)^2 + a(A028234(n)).
a(n) = A005063(A000265(n)).
a(n) = A005079(n) + A005083(n).
(End)

Extensions

More terms from Antti Karttunen, Jul 10 2017

A005075 Sum of squares of primes = 2 mod 3 dividing n.

Original entry on oeis.org

0, 4, 0, 4, 25, 4, 0, 4, 0, 29, 121, 4, 0, 4, 25, 4, 289, 4, 0, 29, 0, 125, 529, 4, 25, 4, 0, 4, 841, 29, 0, 4, 121, 293, 25, 4, 0, 4, 0, 29, 1681, 4, 0, 125, 25, 533, 2209, 4, 0, 29, 289, 4, 2809, 4, 146, 4, 0, 845, 3481, 29, 0, 4, 0, 4, 25, 125, 0, 293, 529, 29, 5041, 4, 0, 4, 25, 4, 121, 4, 0, 29, 0, 1685, 6889, 4, 314
Offset: 1

Views

Author

Keywords

Crossrefs

Programs

  • Mathematica
    Array[DivisorSum[#, #^2 &, And[PrimeQ@ #, Mod[#, 3] == 2] &] &, 85] (* Michael De Vlieger, Jul 11 2017 *)
    f[p_, e_] := If[Mod[p, 3] == 2, p^2, 0]; a[n_] := Plus @@ f @@@ FactorInteger[n]; a[1] = 0; Array[a, 100] (* Amiram Eldar, Jun 21 2022 *)
  • PARI
    a(n) = my(f=factor(n)); sum(k=1, #f~, if (((p=f[k,1])%3) == 2, p^2)); \\ Michel Marcus, Jul 11 2017
  • Scheme
    (define (A005075 n) (if (= 1 n) 0 (+ (A000290 (if (= 2 (modulo (A020639 n) 3)) (A020639 n) 0)) (A005075 (A028234 n))))) ;; Antti Karttunen, Jul 10 2017
    

Formula

Additive with a(p^e) = p^2 if p = 2 (mod 3), 0 otherwise.
a(n) = A005063(n) - A005071(n) - 9*A079978(n). - Antti Karttunen, Jul 10 2017

Extensions

More terms from Antti Karttunen, Jul 10 2017

A200768 Sum of the n-th powers of the distinct prime divisors of n.

Original entry on oeis.org

0, 4, 27, 16, 3125, 793, 823543, 256, 19683, 9766649, 285311670611, 535537, 302875106592253, 678223089233, 30531927032, 65536, 827240261886336764177, 387682633, 1978419655660313589123979, 95367432689201, 558545874543637210, 81402749386839765307625
Offset: 1

Views

Author

Michel Lagneau, Nov 22 2011

Keywords

Examples

			a(6) = 793 because the distinct prime divisors of 6 are 2 and 3, and 2^6 + 3^6 = 793.
		

Crossrefs

Programs

  • Maple
    f:= proc(n) local p;
       add(p^n, p = numtheory:-factorset(n))
    end proc:
    map(f, [$1..30]); # Robert Israel, Feb 20 2024
  • Mathematica
    Prepend[Array[Plus@@First[Transpose[FactorInteger[#]^#]]&,100,2],0]
    Join[{0},Table[Total[FactorInteger[n][[All,1]]^n],{n,2,25}]] (* Harvey P. Dale, Jan 23 2021 *)

Formula

a(n) = Sum_{p|n} p^n. - Wesley Ivan Hurt, Jun 14 2021

A114989 Numbers whose sum of squares of distinct prime factors is prime.

Original entry on oeis.org

6, 10, 12, 14, 18, 20, 24, 26, 28, 34, 36, 40, 48, 50, 52, 54, 56, 68, 72, 74, 80, 94, 96, 98, 100, 104, 105, 108, 112, 134, 136, 144, 146, 148, 160, 162, 188, 192, 194, 196, 200, 206, 208, 216, 224, 231, 250, 268, 272, 273, 274, 288, 292, 296, 315, 320, 324, 326
Offset: 1

Views

Author

Jonathan Vos Post, Feb 22 2006

Keywords

Comments

A005063 is "sum of squares of primes dividing n." Hence this is the sum of squares of prime factors analog of A114522 "numbers n such that sum of distinct prime divisors of n is prime." Note the distinction between A005063 and A067666 is "sum of squares of prime factors of n (counted with multiplicity)."

Examples

			a(1) = 6 because 6 = 2 * 3 and 2^2 + 3^2 = 13 is prime.
a(2) = 10 because 10 = 2 * 5 and 2^2 + 5^2 = 29 is prime.
a(3) = 12 because 12 = 2^2 * 3 and 2^2 + 3^2 = 13 is prime (note that we are not counting the prime factors with multiplicity).
a(4) = 14 because 14 = 2 * 7 and 2^2 + 7^2 = 53 is prime.
a(8) = 26 because 26 = 2 * 3 and 2^2 + 13^2 = 173 is prime.
a(10) = 34 because 34 = 2 * 17 and 2^2 + 17^2 = 293 is prime.
		

Crossrefs

Programs

  • Maple
    with(numtheory): a:=proc(n) local DPF: DPF:=factorset(n): if isprime(sum(DPF[j]^2,j=1..nops(DPF)))=true then n else fi end: seq(a(n),n=1..400); # Emeric Deutsch, Mar 07 2006
  • Mathematica
    Select[Range[400],PrimeQ[Total[Transpose[FactorInteger[#]][[1]]^2]]&] (* Harvey P. Dale, Jan 16 2016 *)
  • PARI
    is(n)=isprime(norml2(factor(n)[,1]))

Formula

{k such that A005063(k) is prime}. {k such that A005063(k) is an element of A000040}. {k = (for distinct i, j, ... prime(i)^e_1 * prime(j)^e_2 * ...) such that (prime(i)^2 * prime(j)^2 * ...) is prime}.

Extensions

More terms from Emeric Deutsch, Mar 07 2006

A144711 Numbers n such that [sum_i=1..r (p(i)^2)]/r = c^2. p(i) prime divisors of n, c integer.

Original entry on oeis.org

2, 3, 4, 5, 7, 8, 9, 11, 13, 16, 17, 19, 23, 25, 27, 29, 31, 32, 37, 41, 43, 47, 49, 53, 59, 61, 64, 67, 71, 73, 79, 81, 83, 89, 97, 101, 103, 107, 109, 113, 119, 121, 125, 127, 128, 131, 137, 139, 149, 151, 157, 161, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211
Offset: 1

Views

Author

Ctibor O. Zizka, Sep 19 2008

Keywords

Comments

A005063(n)/A001221(n) = c^2.
Also numbers n such that the root mean square (quadratic mean) of the prime divisors of n is an integer.
These numbers are power of primes (p^k with k>=1) (A000961) or in A255580. - Daniel Lignon, Feb 26 2015

Crossrefs

Programs

  • Maple
    A005063 := proc(n) add(p^2,p=numtheory[factorset](n)) ; end: A001221 := proc(n) nops(numtheory[factorset](n)) ; end: isA144711 := proc(n) local sofpr ; sofpr := A001221(n) ; if sofpr <> 0 then issqr(A005063(n)/sofpr) ; else false ; fi; end: for n from 1 to 500 do if isA144711(n) then printf("%d,",n) ; fi; od: # R. J. Mathar, Sep 20 2008
  • Mathematica
    Select[Range[2,1000],IntegerQ[RootMeanSquare[Select[Divisors[#],PrimeQ]]]&] (* Daniel Lignon, Feb 26 2015 *)

Extensions

More terms from R. J. Mathar, Sep 20 2008

A189120 Sum of squares of nonprime divisors of n.

Original entry on oeis.org

1, 1, 1, 17, 1, 37, 1, 81, 82, 101, 1, 197, 1, 197, 226, 337, 1, 442, 1, 517, 442, 485, 1, 837, 626, 677, 811, 997, 1, 1262, 1, 1361, 1090, 1157, 1226, 1898, 1, 1445, 1522, 2181, 1, 2438, 1, 2437, 2332, 2117, 1, 3397, 2402, 3226, 2602, 3397, 1, 4087, 3026, 4197, 3250, 3365
Offset: 1

Views

Author

Jonathan Vos Post, Apr 17 2011

Keywords

Comments

a(p) = 1 for p prime.

Examples

			a(12) = 197 because the divisors of 12 are {1, 2, 3, 4, 6, 12}, the subset of nonprime divisors are {1, 4, 6, 12}, and 1^2 + 4^2 + 6^2 + 12^2 = 197.
		

Crossrefs

Cf. A023890 (sum of the nonprime divisors of n).

Programs

  • Maple
    A189120 := proc(n) local a,d; a := 0 ; for d in numtheory[divisors](n) do if not isprime(d) then a := a+d^2 ; end if; end do: a ; end proc: # R. J. Mathar, Apr 17 2011
  • Mathematica
    Table[Total[Select[Divisors[n], ! PrimeQ[#] &]^2], {n, 50}]

Formula

a(n) = Sum_{k|n, k not prime} k^2.
G.f.: Sum_{k>=1} k^2*x^(k+1)/(1 - x^k) - prime(k)^2*x^(prime(k)+1)/(1 - x^prime(k)). - Ilya Gutkovskiy, Jan 01 2017
a(n) = A001157(n) - A005063(n). - Wesley Ivan Hurt, Sep 04 2022
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