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 1-4 of 4 results.

A378136 a(n) = p(2*n*p(n)), where p(x) = least prime > x.

Original entry on oeis.org

2, 5, 13, 31, 41, 71, 89, 157, 179, 199, 223, 293, 313, 443, 479, 521, 547, 647, 691, 877, 929, 967, 1013, 1361, 1399, 1451, 1511, 1567, 1627, 1801, 1861, 2297, 2371, 2447, 2521, 2591, 2671, 3037, 3119, 3203, 3299, 3527, 3613, 4049, 4139, 4231, 4327, 4987, 5099
Offset: 0

Views

Author

Clark Kimberling, Nov 20 2024

Keywords

Examples

			p(0) = 2, so a(0) = p(2*p(0)) = 5.
		

Crossrefs

Programs

  • Mathematica
    Table[NextPrime[2 n*NextPrime[n]], {n, 0, 80}]
  • PARI
    p(n) = nextprime(n+1);
    a(n) = p(2*n*p(n)); \\ Michel Marcus, Nov 21 2024

A378137 a(n) = p(n^2*p(n)), where p(x) is the least prime > x.

Original entry on oeis.org

2, 3, 13, 47, 83, 179, 257, 541, 709, 907, 1103, 1579, 1873, 2879, 3343, 3833, 4357, 5501, 6163, 8311, 9203, 10151, 11149, 15349, 16729, 18127, 19609, 21143, 22739, 26083, 27901, 35569, 37889, 40343, 42773, 45329, 47963, 56131, 59207, 62383, 65609, 72287
Offset: 0

Views

Author

Clark Kimberling, Dec 21 2024

Keywords

Examples

			p(2) = 3, so a(2) = p(4*p(2)) = 13.
		

Crossrefs

Programs

  • Mathematica
    Table[NextPrime[n^2*NextPrime[n]], {n, 0, 80}]

Formula

a(n) = A151800(n^2*A151800(n)).

A379405 a(n) = p((n+1)*p(n)), where p(x) = least prime > x; i.e., p = A151800.

Original entry on oeis.org

3, 5, 11, 23, 29, 43, 53, 89, 101, 113, 127, 157, 173, 239, 257, 277, 293, 347, 367, 461, 487, 509, 541, 701, 727, 757, 787, 821, 853, 937, 967, 1187, 1223, 1259, 1297, 1361, 1373, 1559, 1601, 1657, 1693, 1811, 1861, 2069, 2129, 2179, 2213, 2549, 2609, 2657
Offset: 0

Views

Author

Clark Kimberling, Jan 18 2025

Keywords

Examples

			p(1) = 2, so a(1) = p(2*p(1)) = 5.
		

Crossrefs

Programs

  • Mathematica
    Table[NextPrime[(n+1)*NextPrime[n]], {n, 0, 80}]
  • PARI
    p(n) = nextprime(n+1);
    a(n) = p((n+1)*p(n)); \\ Michel Marcus, Jan 18 2025
    
  • Python
    from sympy import nextprime
    def A379405(n): return nextprime((n+1)*nextprime(n)) # Chai Wah Wu, Jan 20 2025

Formula

a(n) = A151800(A053024(n+1)). - Alois P. Heinz, Jan 18 2025

A380329 a(n) = A151800((n-1)*A151800(n)).

Original entry on oeis.org

2, 2, 5, 11, 17, 29, 37, 67, 79, 89, 101, 131, 149, 211, 223, 239, 257, 307, 331, 419, 439, 461, 487, 641, 673, 701, 727, 757, 787, 877, 907, 1117, 1151, 1187, 1223, 1259, 1297, 1481, 1523, 1559, 1601, 1721, 1777, 1979, 2027, 2069, 2129, 2441, 2503, 2549, 2609
Offset: 0

Views

Author

Clark Kimberling, Jan 21 2025

Keywords

Examples

			p(1) = 2, so a(1) = p(0*p(1)) = 2.
		

Crossrefs

Programs

  • Maple
    seq(nextprime((n-1)*nextprime(n)), n=0..100); # Robert Israel, Jan 23 2025
  • Mathematica
    Table[NextPrime[(n-1)*NextPrime[n]], {n, 0, 80}]
  • PARI
    p(n) = nextprime(n+1);
    a(n) = p((n-1)*p(n)); \\ Michel Marcus, Jan 23 2025
Showing 1-4 of 4 results.