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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A174352 Numbers n such that (n+1)*10^n - 1 is prime.

Original entry on oeis.org

1, 4, 5, 17, 20, 28, 173, 181, 331, 575, 1313, 1754, 4067, 27314
Offset: 1

Views

Author

Rick L. Shepherd, Mar 22 2010

Keywords

Comments

The corresponding primes are in A145851. Primes found and proved by PrimeForm. No more terms up to 30000.

Crossrefs

Cf. A145851.

Programs

A145852 Primes of the form k followed by a 0 and k 9's.

Original entry on oeis.org

109, 2099, 409999, 1909999999999999999999, 2809999999999999999999999999999, 41099999999999999999999999999999999999999999, 7609999999999999999999999999999999999999999999999999999999999999999999999999999
Offset: 1

Views

Author

Lekraj Beedassy, Oct 21 2008

Keywords

Comments

Primes of the form k*10^(k+1) + 10^k - 1.

Crossrefs

Cf. A141311, A145851.

Programs

  • PARI
    lista(nn) = for(k=1, nn, if(ispseudoprime(q=k*10^(k+1)+10^k-1), print1(q, ", "))); \\ Jinyuan Wang, Mar 24 2020
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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