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 1-5 of 5 results.

A275717 Numbers n for which A003961(n) > A003961(n-1).

Original entry on oeis.org

2, 3, 4, 6, 8, 12, 14, 15, 16, 18, 20, 24, 26, 27, 30, 32, 35, 36, 38, 39, 40, 42, 44, 45, 48, 50, 52, 54, 56, 60, 62, 63, 64, 66, 68, 70, 72, 74, 75, 78, 80, 81, 84, 86, 87, 88, 90, 92, 95, 96, 98, 100, 102, 104, 108, 110, 112, 114, 116, 117, 119, 120, 122, 123, 124, 125, 126, 128, 130, 132, 135, 138, 140, 143, 144
Offset: 1

Views

Author

Antti Karttunen, Aug 07 2016

Keywords

Comments

One more than the positions of ascents in permutation A048673.

Crossrefs

One more than A275721.
Complement: A275718 (apart from 1 which is in neither sequence).
Cf. A029744 (a subsequence, apart from its initial 1).

Programs

  • Mathematica
    f[n_] := Times @@ Map[Prime[PrimePi@ First[#] + 1]^Last[#] &, FactorInteger@ n]; Select[Range@ 145, f[# - 1] < f@ # &] (* Michael De Vlieger, Aug 07 2016 *)

A275718 Numbers n for which A003961(n) < A003961(n-1).

Original entry on oeis.org

5, 7, 9, 10, 11, 13, 17, 19, 21, 22, 23, 25, 28, 29, 31, 33, 34, 37, 41, 43, 46, 47, 49, 51, 53, 55, 57, 58, 59, 61, 65, 67, 69, 71, 73, 76, 77, 79, 82, 83, 85, 89, 91, 93, 94, 97, 99, 101, 103, 105, 106, 107, 109, 111, 113, 115, 118, 121, 127, 129, 131, 133, 134, 136, 137, 139, 141, 142, 145, 148, 149, 151, 153, 154, 155
Offset: 1

Views

Author

Antti Karttunen, Aug 07 2016

Keywords

Comments

One more than the positions of descents in permutation A048673.

Crossrefs

One more than A275722.
Complement: A275717 (apart from 1 which is in neither sequence).

Programs

  • Mathematica
    f[n_] := Times @@ Map[Prime[PrimePi@ First[#] + 1]^Last[#] &, FactorInteger@ n]; Select[Range@ 155, f[# - 1] > f@ # &] (* Michael De Vlieger, Aug 07 2016 *)

A275721 Numbers n for which A003961(n+1) > A003961(n).

Original entry on oeis.org

1, 2, 3, 5, 7, 11, 13, 14, 15, 17, 19, 23, 25, 26, 29, 31, 34, 35, 37, 38, 39, 41, 43, 44, 47, 49, 51, 53, 55, 59, 61, 62, 63, 65, 67, 69, 71, 73, 74, 77, 79, 80, 83, 85, 86, 87, 89, 91, 94, 95, 97, 99, 101, 103, 107, 109, 111, 113, 115, 116, 118, 119, 121, 122, 123, 124, 125, 127, 129, 131, 134, 137, 139, 142, 143, 145
Offset: 1

Views

Author

Antti Karttunen, Aug 07 2016

Keywords

Comments

Positions of the ascents in permutation A048673.

Crossrefs

One less than A275717.
Complement: A275722.

Programs

  • Mathematica
    f[n_] := Times @@ Map[Prime[PrimePi@ First[#] + 1]^Last[#] &, FactorInteger@ n]; Select[Range@ 145, f@ # < f[# + 1] &] (* Michael De Vlieger, Aug 07 2016 *)

A275722 Numbers n for which A003961(n+1) < A003961(n).

Original entry on oeis.org

4, 6, 8, 9, 10, 12, 16, 18, 20, 21, 22, 24, 27, 28, 30, 32, 33, 36, 40, 42, 45, 46, 48, 50, 52, 54, 56, 57, 58, 60, 64, 66, 68, 70, 72, 75, 76, 78, 81, 82, 84, 88, 90, 92, 93, 96, 98, 100, 102, 104, 105, 106, 108, 110, 112, 114, 117, 120, 126, 128, 130, 132, 133, 135, 136, 138, 140, 141, 144, 147, 148, 150, 152, 153, 154
Offset: 1

Views

Author

Antti Karttunen, Aug 07 2016

Keywords

Comments

Positions of the descents in permutation A048673.

Crossrefs

One less than A275718.
Complement: A275721.

Programs

  • Mathematica
    f[n_] := Times @@ Map[Prime[PrimePi@ First[#] + 1]^Last[#] &, FactorInteger@ n]; Select[Range@ 154, f@ # > f[# + 1] &] (* Michael De Vlieger, Aug 07 2016 *)

A275720 a(1) = 0; for n > 1, if A003961(n) > A003961(n-1) then a(n) = a(n-1) + 1, otherwise if A003961(n) < A003961(n-1), then a(n) = a(n-1) - 1.

Original entry on oeis.org

0, 1, 2, 3, 2, 3, 2, 3, 2, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 1, 0, 1, 0, 1, 2, 1, 0, 1, 0, 1, 0, -1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 4, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 1, 0, 1, 0, 1, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 4, 3, 2, 3, 2, 3, 4, 3, 2, 3, 2, 3, 4, 5, 4, 5, 4, 5, 4, 3, 4, 5, 4, 5, 4, 5, 4, 5, 4, 5, 4, 3, 2, 3, 2, 3, 2, 3, 2, 3, 2, 3, 4, 3, 4, 5
Offset: 1

Views

Author

Antti Karttunen, Aug 07 2016

Keywords

Crossrefs

Formula

a(1) = 0; for n > 1, if A003961(n) > A003961(n-1) then a(n) = a(n-1) + 1, otherwise if A003961(n) < A003961(n-1), then a(n) = a(n-1) - 1.
Showing 1-5 of 5 results.