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.

A111239 Primes in the order in which they appear in A109890.

Original entry on oeis.org

2, 3, 5, 13, 7, 53, 107, 181, 11, 23, 59, 151, 29, 19, 233, 31, 61, 197, 17, 199, 41, 193, 97, 109, 37, 281, 47, 71, 131, 79, 149, 103, 241, 137, 191, 239, 113, 163, 43, 653, 617, 853, 673, 89, 937, 67, 571, 599, 751, 83, 101, 1103, 829, 457, 499, 229
Offset: 1

Views

Author

N. J. A. Sloane, Oct 30 2005

Keywords

Comments

Smallest missing prime in A109890 for n <= 10^5 is prime(1821) = 15619. - Michael De Vlieger, Apr 27 2024

Crossrefs

Programs

  • Mathematica
    nn = 2^14; c[_] := False;
    Array[Set[{a[#], c[#]}, {#, True}] &, 2];
    s = a[1] + a[2]; v = NextPrime[a[2]];
    t = Join[{{2, 2}},
      Reap[Monitor[Do[k = SelectFirst[Divisors[s], ! c[#] &];
      c[k] = True; s += k;
      If[PrimeQ[k], Sow[{k, n}];
        If[k == v, While[c[v], v = NextPrime[v]]]], {n, 3, nn}], n] ][[-1, 1]] ];
    TakeWhile[t, First[#] <= v &][[All, 1]] (* Michael De Vlieger, Apr 27 2024 *)