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.

Previous Showing 11-14 of 14 results.

A317397 Positive integers that have exactly seven representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.

Original entry on oeis.org

1613, 3321, 3336, 3368, 3741, 3914, 3979, 4082, 4126, 4219, 4561, 4777, 4798, 4824, 4929, 4936, 4948, 5083, 5314, 5371, 5559, 5656, 5825, 5877, 5946, 5986, 6096, 6109, 6111, 6291, 6303, 6376, 6644, 6651, 6673, 6700, 6711, 6786, 6883, 6886, 6917, 6920, 7036
Offset: 1

Views

Author

Alois P. Heinz, Jul 27 2018

Keywords

Crossrefs

Column k=7 of A317390.
Cf. A317241.

Programs

  • Maple
    b:= proc(n, s) option remember; local p, r; if n=1 then 1 else r:=0;
          for p in numtheory[factorset](n-1) minus s while r<8
            do r:= r+b((n-1)/p, s union {p}) od; `if`(r<8, r, 8)
          fi
        end:
    a:= proc(n) option remember; local k; for k from
         `if`(n=1, 1, 1+a(n-1)) while b(k, {})<>7 do od; k
        end:
    seq(a(n), n=1..100);

Formula

A317241(a(n)) = 7.

A317398 Positive integers that have exactly eight representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.

Original entry on oeis.org

2991, 3004, 3319, 3554, 3928, 4846, 5552, 5886, 6293, 6784, 7183, 7286, 7396, 7668, 7741, 7743, 7829, 7996, 8095, 8121, 8212, 8477, 8586, 8614, 8856, 8861, 9096, 9307, 9374, 9591, 9626, 9636, 9637, 9721, 9738, 9845, 9891, 9912, 9934, 10011, 10024, 10048, 10251
Offset: 1

Views

Author

Alois P. Heinz, Jul 27 2018

Keywords

Crossrefs

Column k=8 of A317390.
Cf. A317241.

Programs

  • Maple
    b:= proc(n, s) option remember; local p, r; if n=1 then 1 else r:=0;
          for p in numtheory[factorset](n-1) minus s while r<9
            do r:= r+b((n-1)/p, s union {p}) od; `if`(r<9, r, 9)
          fi
        end:
    a:= proc(n) option remember; local k; for k from
         `if`(n=1, 1, 1+a(n-1)) while b(k, {})<>8 do od; k
        end:
    seq(a(n), n=1..100);

Formula

A317241(a(n)) = 8.

A317399 Positive integers that have exactly nine representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.

Original entry on oeis.org

7021, 7162, 8053, 8737, 9178, 9556, 10126, 10858, 10861, 10866, 11113, 11133, 11363, 11740, 12076, 12111, 12666, 13168, 13210, 13339, 13573, 13729, 14037, 14366, 14411, 14691, 15250, 15478, 15569, 15653, 15726, 15922, 16066, 16113, 16116, 16386, 16459, 16644
Offset: 1

Views

Author

Alois P. Heinz, Jul 27 2018

Keywords

Crossrefs

Column k=9 of A317390.
Cf. A317241.

Programs

  • Maple
    b:= proc(n, s) option remember; local p, r; if n=1 then 1 else r:=0;
          for p in numtheory[factorset](n-1) minus s while r<10
            do r:= r+b((n-1)/p, s union {p}) od; `if`(r<10, r, 10)
          fi
        end:
    a:= proc(n) option remember; local k; for k from
         `if`(n=1, 1, 1+a(n-1)) while b(k, {})<>9 do od; k
        end:
    seq(a(n), n=1..100);

Formula

A317241(a(n)) = 9.

A317400 Positive integers that have exactly ten representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.

Original entry on oeis.org

11306, 13289, 13693, 16402, 16446, 16491, 16699, 17031, 17113, 17116, 17263, 17576, 18412, 18602, 19825, 20023, 20411, 21022, 21256, 21676, 21936, 22271, 22543, 22716, 22764, 23038, 23233, 23332, 23353, 23580, 23599, 23886, 24036, 24053, 24064, 24531, 24646
Offset: 1

Views

Author

Alois P. Heinz, Jul 27 2018

Keywords

Crossrefs

Column k=10 of A317390.
Cf. A317241.

Programs

  • Maple
    b:= proc(n, s) option remember; local p, r; if n=1 then 1 else r:=0;
          for p in numtheory[factorset](n-1) minus s while r<11
            do r:= r+b((n-1)/p, s union {p}) od; `if`(r<11, r, 11)
          fi
        end:
    a:= proc(n) option remember; local k; for k from
         `if`(n=1, 1, 1+a(n-1)) while b(k, {})<>10 do od; k
        end:
    seq(a(n), n=1..100);

Formula

A317241(a(n)) = 10.
Previous Showing 11-14 of 14 results.