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.

A370009 a(n) is the least prime greater than 3*prime(n).

Original entry on oeis.org

7, 11, 17, 23, 37, 41, 53, 59, 71, 89, 97, 113, 127, 131, 149, 163, 179, 191, 211, 223, 223, 239, 251, 269, 293, 307, 311, 331, 331, 347, 383, 397, 419, 419, 449, 457, 479, 491, 503, 521, 541, 547, 577, 587, 593, 599, 641, 673, 683, 691, 701, 719, 727, 757
Offset: 1

Views

Author

Clark Kimberling, Feb 09 2024

Keywords

Examples

			5 < 3*2 < 7 < 3*3 < 11 < 13 < 3*5 < 17, so (a(1), a(2), a(3)) = (7,11,17).

Crossrefs

Cf. A000040, A001748, A059786, A059788, A151800, A370008.

Programs

  • Mathematica
    Table[NextPrime[Prime[PrimePi[3*Prime[n]]]], {n,1,200}]
  • PARI
    a(n) = nextprime(3*prime(n)); \\ Michel Marcus, Feb 10 2024

Formula

a(n) = A151800(A001748(n)).

A370010 a(n) is the greatest prime less than 4*prime(n).

Original entry on oeis.org

7, 11, 19, 23, 43, 47, 67, 73, 89, 113, 113, 139, 163, 167, 181, 211, 233, 241, 263, 283, 283, 313, 331, 353, 383, 401, 409, 421, 433, 449, 503, 523, 547, 547, 593, 601, 619, 647, 661, 691, 709, 719, 761, 769, 787, 787, 839, 887, 907, 911, 929, 953, 953, 997
Offset: 1

Views

Author

Clark Kimberling, Feb 09 2024

Keywords

Examples

			7 < 4*2 < 11 < 4*3 < 13 < 17 < 19  < 5*3 < 23, so (a(1), a(2), a(3)) = (7,11,19).

Crossrefs

Cf. A000040, A001749, A059786, A059788, A370008, A370011.

Programs

  • Mathematica
    Table[Prime[PrimePi[4*Prime[n]]], {n,1,200}]
  • PARI
    a(n) = precprime(4*prime(n)); \\ Michel Marcus, Feb 10 2024

A370011 a(n) is the least prime greater than 4*prime(n).

Original entry on oeis.org

11, 13, 23, 29, 47, 53, 71, 79, 97, 127, 127, 149, 167, 173, 191, 223, 239, 251, 269, 293, 293, 317, 337, 359, 389, 409, 419, 431, 439, 457, 509, 541, 557, 557, 599, 607, 631, 653, 673, 701, 719, 727, 769, 773, 797, 797, 853, 907, 911, 919, 937, 967, 967
Offset: 1

Views

Author

Clark Kimberling, Feb 09 2024

Keywords

Examples

			7 < 4*2 < 11 < 4*3 < 13 < 17 < 19 < 4*5 < 23, so (a(1), a(2), a(3)) = (11,13,23).

Crossrefs

Cf. A000040, A001749, A059786, A059788, A370008, A370010.

Programs

  • Mathematica
    Table[NextPrime[Prime[PrimePi[4*Prime[n]]]], {n, 1, 200}]
  • PARI
    a(n) = nextprime(4*prime(n)); \\ Michel Marcus, Feb 10 2024
Showing 1-3 of 3 results.

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

Content is available under The OEIS End-User License Agreement.