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.

Showing 1-10 of 30 results. Next

A086242 Decimal expansion of the sum of 1/(p-1)^2 over all primes p.

Original entry on oeis.org

1, 3, 7, 5, 0, 6, 4, 9, 9, 4, 7, 4, 8, 6, 3, 5, 2, 8, 7, 9, 1, 7, 2, 5, 3, 1, 3, 0, 5, 2, 2, 4, 3, 9, 6, 9, 9, 1, 7, 9, 5, 9, 9, 9, 6, 0, 1, 7, 5, 3, 1, 7, 4, 5, 8, 7, 0, 9, 1, 8, 9, 3, 3, 5, 8, 9, 1, 2, 3, 5, 7, 1, 3, 1, 4, 1, 5, 5, 5, 2, 5, 5, 4, 2, 9, 9, 0, 7, 6, 5, 2, 4, 1, 6, 5, 8, 8, 1, 1, 4, 5, 2, 7, 6, 0, 6, 5, 7, 4, 4, 8, 0, 6, 5, 7, 4
Offset: 1

Views

Author

Eric W. Weisstein, Jul 13 2003

Keywords

Examples

			1.37506499474863528791725313052243969917959996017...
		

References

  • Henri Cohen, Number Theory, Volume II: Analytic and Modern Tools, GTM Vol. 240, Springer, 2007; see pp. 208-209.
  • Steven R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, Vol. 94, Cambridge University Press, 2003, pp. 94-98.

Crossrefs

Programs

  • Mathematica
    digits = 116; Np = NSum[(n-1)*PrimeZetaP[n], {n, 2, Infinity}, NSumTerms -> 3*digits, WorkingPrecision -> digits+10]; RealDigits[Np, 10, digits] // First (* Jean-François Alcover, Sep 02 2015 *)
  • PARI
    default(realprecision,256);
    (f(k)=return(sum(n=1,1024,moebius(n)/n*log(zeta(k*n)))));
    sum(k=2,1024,(k-1)*f(k)) /* Robert Gerbicz, Sep 12 2012 */
    
  • PARI
    sumeulerrat(1/(p-1)^2) \\ Amiram Eldar, Mar 19 2021

Formula

Equals Sum_{k>=2} (k-1)*primezeta(k). - Robert Gerbicz, Sep 12 2012
Equals lim_{n -> oo} A119686(n)/A334746(n). - Petros Hadjicostas, May 11 2020
Equals Sum_{k>=2} (J_2(k)-phi(k)) * log(zeta(k)) / k, where J_2 = A007434 and phi = A000010 (Jakimczuk, 2017). - Amiram Eldar, Mar 18 2024

Extensions

More digits copied from Cohen's paper by R. J. Mathar, Dec 05 2008
More terms from Robert Gerbicz, Sep 12 2012

A382555 Decimal expansion of Sum_{p prime} 1/(p + 1)^3.

Original entry on oeis.org

0, 6, 0, 7, 1, 6, 2, 9, 6, 4, 8, 7, 1, 3, 6, 3, 7, 2, 8, 4, 7, 3, 9, 8, 5, 9, 8, 8, 2, 8, 0, 9, 1, 3, 2, 4, 7, 2, 0, 3, 2, 6, 7, 4, 4, 3, 7, 1, 6, 9, 1, 2, 4, 2, 6, 1, 9, 3, 1, 5, 3, 6, 8, 3, 0, 5, 1, 1, 5, 5, 2, 9, 0, 6, 0, 0, 0, 3, 2, 5, 5, 8, 3, 4, 2, 7, 8, 9, 3, 9, 8, 0, 4, 1, 8, 4
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.0607162964871363728473985988280913247203267...
		

Crossrefs

Programs

Formula

Equals Sum_{k>=3} (-1)^(k+1) * ((k-2)*(k-1)/2) * P(k), where P is the prime zeta function. - Amiram Eldar, Apr 02 2025

A324833 Decimal expansion of eta_2, a constant related to the asymptotic density of certain sets of residues.

Original entry on oeis.org

1, 2, 9, 0, 3, 8, 9, 2, 5, 8, 9, 7, 8, 0, 7, 5, 5, 6, 4, 9, 7, 4, 3, 4, 8, 6, 3, 4, 8, 1, 7, 7, 5, 8, 7, 7, 6, 3, 8, 4, 9, 3, 2, 1, 4, 1, 9, 9, 2, 0, 5, 6, 8, 8, 3, 0, 0, 4, 1, 2, 7, 0, 4, 5, 6, 3, 9, 8, 0, 6, 6, 5, 7, 3, 0, 9, 1, 7, 0, 3, 9, 8, 9, 9, 9, 7, 1, 6, 7, 7, 8, 3, 5, 9, 8, 1, 9, 3, 4, 3, 8
Offset: 0

Views

Author

Jean-François Alcover, Mar 17 2019

Keywords

Examples

			0.12903892589780755649743486348177587763849321419920568830041270456398...
		

Crossrefs

Cf. A154945 (eta_1), A324834 (eta_3), A324835 (eta_4), A324836 (eta_5).

Programs

  • Mathematica
    digits = 101; m0 = 2 digits; Clear[rd]; rd[m_] := rd[m] = RealDigits[eta2 = Sum[n PrimeZetaP[2n + 2], {n, 1, m}], 10, digits][[1]]; rd[m0]; rd[m = 2m0]; While[rd[m] != rd[m-m0], Print[m]; m = m+m0]; Print[N[eta2, digits] ]; rd[m]

Formula

Sum_{p prime} 1/(p^2-1)^2.
Sum_{n>0} n P(2n+2) where P is the prime zeta P function.
Equals - A136141/4 + A086242/4 - A179119/4 + A382554/4. - Artur Jasinski, Mar 31 2025

A324834 Decimal expansion of eta_3, a constant related to the asymptotic density of certain sets of residues.

Original entry on oeis.org

0, 3, 9, 0, 7, 2, 4, 0, 5, 7, 3, 5, 5, 7, 4, 7, 9, 1, 8, 8, 7, 6, 5, 9, 5, 0, 3, 3, 2, 0, 4, 2, 2, 9, 7, 6, 3, 8, 6, 6, 8, 4, 8, 3, 8, 2, 4, 4, 7, 7, 3, 3, 6, 0, 3, 5, 6, 7, 5, 4, 0, 6, 6, 0, 3, 2, 6, 9, 1, 7, 5, 8, 3, 7, 6, 1, 9, 2, 4, 9, 2, 0, 2, 9, 8, 1, 7, 9, 1, 0, 0, 6, 9, 0, 7, 6, 8, 0, 0, 5, 6, 2, 3
Offset: 0

Views

Author

Jean-François Alcover, Mar 17 2019

Keywords

Examples

			0.03907240573557479188765950332042297638668483824477336035675406603269...
		

Crossrefs

Cf. A154945 (eta_1), A324833 (eta_2), A324835 (eta_4), A324836 (eta_5).

Programs

  • Mathematica
    digits = 102; m0 = 2 digits; Clear[rd]; rd[m_] := rd[m] = RealDigits[eta3 = Sum[n (n+1)/2 PrimeZetaP[2 n + 4], {n, 1, m}] , 10, digits][[1]]; rd[m0]; rd[m = 2 m0]; While[rd[m] != rd[m-m0], Print[m]; m = m+m0]; Print[N[eta3, digits]]; rd[m]

Formula

Sum_{p prime} 1/(p^2-1)^3.
Sum_{n>0} (n(n+1)/2) P(2n+4) where P is the prime zeta P function.
Equals 3*A136141/16 - 3*A086242/16 + A380840/8 + 3*A179119/16 - 3*A382554/16 - A382555/8. - Artur Jasinski, Mar 31 2025

A110833 a(n) = (prime(n)+1)^2.

Original entry on oeis.org

9, 16, 36, 64, 144, 196, 324, 400, 576, 900, 1024, 1444, 1764, 1936, 2304, 2916, 3600, 3844, 4624, 5184, 5476, 6400, 7056, 8100, 9604, 10404, 10816, 11664, 12100, 12996, 16384, 17424, 19044, 19600, 22500, 23104, 24964, 26896, 28224, 30276, 32400, 33124, 36864
Offset: 1

Views

Author

Giovanni Teofilatto, Sep 18 2005

Keywords

Crossrefs

Programs

  • Magma
    [(p+1)^2: p in PrimesUpTo(200)]; // Vincenzo Librandi, Mar 27 2014
    
  • Mathematica
    Table[(Prime[n] + 1)^2, {n, 200}] (* Vincenzo Librandi, Mar 27 2014 *)
  • Python
    from sympy import primerange
    print([(p+1)**2 for p in primerange(1, 192)]) # Michael S. Branicky, Sep 16 2021

Formula

From Amiram Eldar, Jan 23 2021: (Start)
a(n) = A008864(n)^2.
Product_{n>=1} (1 + 1/a(n)) = A065486.
Product_{n>=1} (1 - 1/a(n)) = A065472. (End)
Sum 1/a(n) = A382554. - R. J. Mathar, Mar 31 2025

Extensions

Corrected and extended by Ray Chandler, Oct 08 2005

A382567 Decimal expansion of Sum_{p prime} 1/(p*(p + 1)^2).

Original entry on oeis.org

0, 8, 5, 7, 5, 2, 6, 2, 2, 1, 0, 7, 6, 0, 9, 9, 3, 4, 0, 6, 3, 1, 4, 6, 2, 1, 6, 7, 3, 9, 3, 9, 3, 7, 9, 3, 0, 0, 6, 8, 8, 5, 7, 6, 7, 2, 9, 5, 3, 0, 8, 6, 5, 7, 1, 9, 6, 5, 3, 2, 4, 5, 0, 2, 7, 8, 6, 0, 4, 0, 2, 1, 7, 2, 8, 6, 5, 3, 6, 9, 7, 9, 9, 6, 2, 2, 2, 1, 8, 2, 2, 4, 9, 3, 3, 9, 5, 5, 8, 6, 7, 7, 9, 5
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.0857526221076099340631462167393937930068857672953086571965324502786040217286...
		

Crossrefs

Programs

  • PARI
    sumeulerrat(1/(p*(p+1)^2)) \\ Amiram Eldar, Apr 01 2025

Formula

Equals A179119 - A382554.
Equals Sum_{k>=3} (-1)^(k+1) * (k-2) * P(k), where P is the prime zeta function. - Amiram Eldar, Apr 01 2025

A382568 Decimal expansion of Sum_{p prime} 1/(p^2*(p + 1)^2).

Original entry on oeis.org

0, 3, 6, 2, 6, 4, 8, 7, 1, 6, 6, 9, 2, 5, 2, 3, 2, 3, 4, 2, 8, 3, 0, 2, 5, 6, 0, 0, 0, 6, 1, 0, 9, 3, 8, 0, 5, 2, 2, 0, 8, 6, 1, 5, 6, 4, 7, 0, 5, 1, 3, 3, 0, 8, 3, 8, 9, 6, 5, 7, 8, 7, 9, 3, 1, 0, 1, 3, 8, 8, 3, 8, 8, 4, 2, 3, 4, 9, 2, 3, 2, 1, 3, 1, 0, 3, 2, 1, 5, 4, 5, 9, 2, 3, 3, 2, 1, 9, 6, 4, 2, 3, 6, 7, 4
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.03626487166925232342830256000610938052208615647051330838965787931013...
		

Crossrefs

Programs

  • PARI
    sumeulerrat(1/(p^2*(p+1)^2)) \\ Amiram Eldar, Apr 01 2025

Formula

Equals A085548 - 2*A179119 + A382554.
Equals Sum_{k>=4} (-1)^k * (k-3) * P(k), where P is the prime zeta function. - Amiram Eldar, Apr 01 2025

A382569 Decimal expansion of Sum_{p prime} 1/(p^3*(p + 1)^2).

Original entry on oeis.org

0, 1, 6, 4, 8, 0, 2, 7, 3, 8, 5, 3, 3, 2, 8, 9, 5, 5, 5, 0, 3, 3, 6, 1, 9, 7, 7, 9, 1, 4, 0, 9, 4, 1, 4, 6, 9, 2, 4, 3, 5, 4, 0, 4, 1, 6, 8, 9, 8, 1, 4, 0, 1, 5, 9, 1, 2, 8, 2, 3, 8, 0, 7, 8, 0, 2, 7, 4, 9, 8, 9, 0, 1, 1, 4, 7, 7, 7, 4, 2, 5, 3, 7, 7, 3, 4, 7, 7, 0, 9, 1, 0, 2, 9, 6, 8, 6, 0, 9, 0, 2, 1, 4, 8
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.016480273853328955503361977914094146924354041689814015912823807...
		

Crossrefs

Programs

  • PARI
    sumeulerrat(1/(p^3*(p+1)^2)) \\ Amiram Eldar, Apr 01 2025

Formula

Equals -2*A085548 + A085541 + 3*A179119 - A382554.
Equals Sum_{k>=5} (-1)^(k+1) * (k-4) * P(k), where P is the prime zeta function. - Amiram Eldar, Apr 01 2025

A382571 Decimal expansion of Sum_{p prime} 1/((p - 1)*(p + 1)^2).

Original entry on oeis.org

1, 5, 3, 6, 0, 7, 9, 9, 6, 7, 5, 0, 2, 0, 2, 9, 3, 8, 7, 4, 3, 8, 9, 1, 3, 2, 6, 3, 1, 1, 9, 9, 6, 3, 0, 5, 2, 4, 7, 0, 6, 3, 3, 6, 2, 7, 9, 9, 9, 3, 3, 2, 2, 6, 6, 3, 8, 4, 6, 0, 5, 9, 1, 7, 8, 7, 8, 7, 3, 7, 2, 6, 2, 8, 8, 4, 0, 8, 2, 1, 2, 3, 7, 6, 1, 3, 4, 9, 7, 8, 9, 5, 2, 1, 9, 1, 2, 0, 8, 1, 4, 0
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.153607996750202938743891326311996305247063362799933226638460591787...
		

Crossrefs

Programs

  • PARI
    sumeulerrat(1/((p-1)*(p+1)^2)) \\ Amiram Eldar, Apr 02 2025

Formula

Equals A136141/4 + A179119/4 - A382554/2.
Equals Sum_{k>=2} (k-1) * (P(2*k-1) - P(2*k)), where P is the prime zeta function. - Amiram Eldar, Apr 02 2025

A382573 Decimal expansion of Sum_{p prime} 1/((p - 1)^3*(p + 1)^2).

Original entry on oeis.org

1, 1, 9, 4, 4, 1, 3, 4, 9, 3, 5, 4, 2, 8, 6, 7, 2, 0, 5, 4, 9, 9, 1, 3, 2, 5, 6, 5, 1, 0, 7, 5, 7, 6, 4, 6, 4, 6, 0, 9, 3, 2, 1, 2, 8, 9, 8, 2, 0, 8, 9, 0, 6, 8, 8, 5, 8, 9, 2, 8, 1, 7, 8, 4, 7, 6, 6, 8, 4, 3, 0, 0, 3, 1, 0, 7, 4, 2, 2, 6, 4, 8, 7, 4, 1, 5, 7, 6, 4, 9, 2, 6, 9, 1, 4, 3, 0, 0, 0, 2, 7, 2
Offset: 0

Views

Author

Artur Jasinski, Mar 31 2025

Keywords

Examples

			0.119441349354286720549913256510757646460932...
		

Crossrefs

Programs

  • PARI
    sumeulerrat(1/((p-1)^3*(p+1)^2)) \\ Amiram Eldar, Apr 02 2025

Formula

Equals 3*A136141/16 - A086242/4 + A380840/4 + 3*A179119/16 - A382554/8.
Equals Sum_{k>=3} ((k-2)*(k-1)/2) * (P(2*k-1) + P(2*k)), where P is the prime zeta function. - Amiram Eldar, Apr 02 2025
Showing 1-10 of 30 results. Next