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 1-3 of 3 results.

A021247 Decimal expansion of 1/243.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Dec 11 1996

Keywords

Comments

Period 27 Repeat: [0, 0, 4, 1, 1, 5, 2, 2, 6, 3, 3, 7, 4, 4, 8, 5, 5, 9, 6, 7, 0, 7, 8, 1, 8, 9, 3]. - Wesley Ivan Hurt, May 25 2014

Examples

			0.00411522633744855967078189300411522633744855967078189300411522633744855967078...
		

Crossrefs

Cf. A010701 (1/3), A000012 (1/3^2), A021085 (1/3^4), A021733 (1/3^6).
Cf. A068542 (period of the fraction 1/3^n).

Programs

  • Maple
    Digits:=100; evalf(1/243); # Wesley Ivan Hurt, May 25 2014
  • Mathematica
    RealDigits[1/243, 10, 100, -1][[1]] (* Wesley Ivan Hurt, May 25 2014; corrected by Harvey P. Dale, Jan 23 2019 *)
    PadRight[{},120,{0,0,4,1,1,5,2,2,6,3,3,7,4,4,8,5,5,9,6,7,0,7,8,1,8,9,3}] (* Harvey P. Dale, Jan 23 2019 *)
  • PARI
    A021247_upto(N=100)={localprec(N+3);digits((1/3^5+1)\.1^N)[^1]} \\ M. F. Hasler, Apr 23 2021

Formula

1/243 = 1/3^5. - M. F. Hasler, Apr 23 2021

A343616 Decimal expansion of P_{3,2}(6) = Sum 1/p^6 over primes == 2 (mod 3).

Original entry on oeis.org

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

Views

Author

M. F. Hasler, Apr 25 2021

Keywords

Comments

The prime zeta modulo function P_{m,r}(s) = Sum_{primes p == r (mod m)} 1/p^s generalizes the prime zeta function P(s) = Sum_{primes p} 1/p^s.

Examples

			0.015689614727130461563527666152209091814208675553077763366153188676457...
		

Crossrefs

Cf. A003627 (primes 3k-1), A001014 (n^6), A085966 (PrimeZeta(6)), A021733 (1/3^6).
Cf. A343612 - A343619 (P_{3,2}(s): analog for 1/p^s, s = 2 .. 9).
Cf. A343626 (for primes 3k+1), A086036 (for primes 4k+1), A085995 (for primes 4k+3).

Programs

  • PARI
    A343616_upto(N=100)={localprec(N+5); digits((PrimeZeta32(6)+1)\.1^N)[^1]} \\ see A343612 for the function PrimeZeta32

Formula

P_{3,2}(6) = Sum_{p in A003627} 1/p^6 = P(6) - 1/3^6 - P_{3,1}(6).

A384917 Decimal expansion of 1/3645.

Original entry on oeis.org

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

Views

Author

Davide Rotondo, Jun 12 2025

Keywords

Examples

			0.0002743484224965706447187928669410...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[1/3645, 10, 120, -1][[1]] (* Amiram Eldar, Jun 12 2025 *)

Formula

Equals Sum_{k>=1} (k*(k+1))/10^(k+3).
Equals A021733/5. - Hugo Pfoertner, Jun 12 2025
Showing 1-3 of 3 results.