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.

A144812 Integers having ideal digital mean up to base 7.

Original entry on oeis.org

36990, 37230, 43350, 45390, 2149023720, 2149218300, 2149279740, 2149513020, 2149527540, 2149545960, 2151079740, 2151628020, 2151662460, 2151667320, 2152716540, 2152720860, 2152724280, 2153463540, 2154166200, 2154948600, 2155019220, 2155051980, 2155196340
Offset: 1

Views

Author

Reikku Kulon, Sep 21 2008

Keywords

Comments

These numbers have digital mean dm(b, n) = (Sum_{i=1..d} 2*d_i - (b-1)) / (2*d) = 0, where d is the number of digits in the base b representation of n and d_i the individual digits, for 2 <= b <= 7.
There are no integers less than 2^32 for which this is true to base 8. It is believed there are either infinitely many starting at some larger n, or none. If they exist, it is conjectured that the set of all similar sequences continues at least to base ten, almost certainly to base 16 and likely to arbitrarily large b. Sequences for b at least ten have an intersection with A144777.

Crossrefs

A144798 Integers having ideal digital mean up to base 3.

Original entry on oeis.org

38, 42, 56, 139, 141, 147, 153, 169, 177, 195, 201, 225, 542, 558, 572, 598, 604, 654, 666, 678, 684, 779, 781, 803, 805, 835, 899, 905, 913, 929, 2079, 2107, 2109, 2266, 2390, 2396, 2410, 2418, 2424, 2474, 2482, 2506, 2508, 2536, 2606, 2614, 2638, 2650
Offset: 1

Views

Author

Reikku Kulon, Sep 21 2008

Keywords

Comments

Subset of A031443.
These numbers have digital mean dm(b, n) = (Sum_{i=1..d} 2*d_i - (b-1)) / (2*d) = 0, where d is the number of digits in the base b representation of n and d_i the individual digits, for 2 <= b <= 3.

Crossrefs

Extensions

Added accidentally omitted terms. - Reikku Kulon, Sep 24 2008

A144799 Integers having ideal digital mean up to base 4.

Original entry on oeis.org

141, 147, 153, 177, 195, 201, 225, 2079, 2109, 2418, 2424, 2508, 2652, 2868, 2892, 2898, 3102, 3126, 3150, 3228, 3282, 3288, 3300, 3312, 3342, 3354, 3366, 3378, 3384, 3426, 3462, 3468, 3474, 3504, 3522, 3528, 3696, 3792, 3846, 3852, 3864, 3912, 3936
Offset: 1

Views

Author

Reikku Kulon, Sep 21 2008

Keywords

Comments

Subset of A031443 and A144798.
These numbers have digital mean dm(b, n) = (Sum_{i=1..d} 2*d_i - (b-1)) / (2*d) = 0, where d is the number of digits in the base b representation of n and d_i the individual digits, for 2 <= b <= 4.

Crossrefs

Extensions

Added accidentally omitted terms. - Reikku Kulon, Sep 24 2008

A144800 Integers having ideal digital mean up to base 5.

Original entry on oeis.org

3468, 3696, 3864, 3984, 33918, 34158, 34674, 36294, 36990, 37230, 37302, 37326, 37722, 38046, 38106, 38322, 38478, 38670, 38682, 38730, 40038, 40086, 40326, 40722, 41334, 43350, 45270, 45390, 49278, 49518, 49638, 49878, 49950, 50478, 50586, 50610, 50718, 50742
Offset: 1

Views

Author

Reikku Kulon, Sep 21 2008

Keywords

Comments

Subset of A031443, A144798 and A144799.
These numbers have digital mean dm(b, n) = (Sum_{i=1..d} 2*d_i - (b-1)) / (2*d) = 0, where d is the number of digits in the base b representation of n and d_i the individual digits, for 2 <= b <= 5.

Crossrefs

Extensions

Added accidentally omitted terms. - Reikku Kulon, Sep 24 2008

A144801 Integers having ideal digital mean up to base 6.

Original entry on oeis.org

36990, 37230, 38670, 43350, 45390, 14492490, 14496810, 14512170, 14578050, 14579970, 14630970, 14655810, 14663730, 14685690, 14733810, 14741790, 14753010, 14758350, 14761350, 14779230, 14779710, 14780310, 14784090, 14801490, 14807190, 14807430, 14818650
Offset: 1

Views

Author

Reikku Kulon, Sep 21 2008

Keywords

Comments

Subset of A031443, A144798, A144799 and A144800.
These numbers have digital mean dm(b, n) = (Sum_{i=1..d} 2*d_i - (b-1)) / (2*d) = 0, where d is the number of digits in the base b representation of n and d_i the individual digits, for 2 <= b <= 6.

Crossrefs

Programs

  • PARI
    is(k,b) = my(d=digits(k,b)); vecsum(d)/#d == (b-1)/2;
    isok(k) = is(k,2) && is(k,3) && is(k,4) && is(k,5) && is(k,6); \\ Michel Marcus, Aug 03 2023

Extensions

Accidentally omitted terms added by Reikku Kulon, Sep 24 2008
a(24)-a(27) from Pontus von Brömssen, Aug 02 2023
Showing 1-5 of 5 results.