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.

A192110 Monotonic ordering of nonnegative differences 2^i - 3^j, for 40 >= i >= 0, j >= 0.

Original entry on oeis.org

0, 1, 3, 5, 7, 13, 15, 23, 29, 31, 37, 47, 55, 61, 63, 101, 119, 125, 127, 175, 229, 247, 253, 255, 269, 295, 431, 485, 503, 509, 511, 781, 943, 997, 1015, 1021, 1023, 1319, 1631, 1805, 1909, 1967, 2021, 2039, 2045, 2047, 3367, 3853, 4015, 4069, 4087, 4093
Offset: 1

Views

Author

Clark Kimberling, Jun 23 2011

Keywords

Comments

Comments from N. J. A. Sloane, Oct 21 2019: (Start)
Warning: Note the definition assumes i <= 40.
Because of this assumption, it is not true that this is (except for a(1)=0) the complement of A075824 in the odd integers.
However, by definition, it is the complement of A328077.
(End)
All 52 sequences in this set are finite. - Georg Fischer, Nov 16 2021

Examples

			The differences accrue like this:
1-1
2-1
4-3.....4-1
8-3.....8-1
16-9....16-3....16-1
32-27...32-9....32-3....32-1
64-27...64-9....64-3....64-1
		

Crossrefs

Cf. A075824, A173671, A192111, A328077 (complement).
For primes, see A007643, A007644, A321671.
This is the first of a set of 52 similar sequences:
A192110: 2^i-3^j, A192111: 3^i-2^j, A192112: 2^i-4^j, A192113: 4^i-2^j, A192114: 2^i-5^j, A192115: 5^i-2^j, A192116: 2^i-6^j, A192117: 6^i-2^j,
A192118: 2^i-7^j, A192119: 7^i-2^j, A192120: 2^i-8^j, A192121: 8^i-2^j, A192122: 2^i-9^j, A192123: 9^i-2^j, A192124: 2^i-10^j, A192125: 10^i-2^j,
A192147: 3^i-4^j, A192148: 4^i-3^j, A192149: 3^i-5^j, A192150: 5^i-3^j, A192151: 3^i-6^j, A192152: 6^i-3^j, A192153: 3^i-7^j, A192154: 7^i-3^j,
A192155: 3^i-8^j, A192156: 8^i-3^j, A192157: 3^i-9^j, A192158: 9^i-3^j, A192159: 3^i-10^j, A192160: 10^i-3^j, A192161: 4^i-5^j, A192162: 5^i-4^j,
A192163: 4^i-6^j, A192164: 6^i-4^j, A192165: 4^i-7^j, A192166: 7^i-4^j, A192167: 4^i-8^j, A192168: 8^i-4^j, A192169: 4^i-9^j, A192170: 9^i-4^j,
A192171: 4^i-10^j, A192172: 10^i-4^j, A192193: 5^i-6^j, A192194: 6^i-5^j, A192195: 5^i-7^j, A192196: 7^i-5^j, A192197: 5^i-8^j, A192198: 8^i-5^j,
A192199: 5^i-9^j, A192200: 9^i-5^j, A192201: 5^i-10^j, A192202: 10^i-5^j.

Programs

  • Mathematica
    c = 2; d = 3; t[i_, j_] := c^i - d^j;
    u = Table[t[i, j], {i, 0, 40}, {j, 0, i*Log[d, c]}];
    v = Union[Flatten[u ]]

A192111 Monotonic ordering of nonnegative differences 3^i-2^j, for i>=0, j>=0.

Original entry on oeis.org

0, 1, 2, 5, 7, 8, 11, 17, 19, 23, 25, 26, 49, 65, 73, 77, 79, 80
Offset: 1

Views

Author

Clark Kimberling, Jun 23 2011

Keywords

Comments

Complement of A173671 in the nonnegative integers.

Crossrefs

Cf. A173671 (complement), A192110, A227048 (partial unions of rows).

Extensions

Deleted unwarranted programs and b-file. Only the terms in A173671 (that is, up to 100) have been proved to be correct. - N. J. A. Sloane, Oct 21 2019

A328077 Complement of A192110.

Original entry on oeis.org

2, 4, 6, 8, 9, 10, 11, 12, 14, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 30, 32, 33, 34, 35, 36, 38, 39, 40, 41, 42, 43, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 62, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80
Offset: 1

Views

Author

N. J. A. Sloane, Oct 12 2019

Keywords

Comments

Note that, because A192110 assumes i <= 40, it is incorrect to say that the present sequence consists of "the positive integers that cannot be expressed as 2^m-3^n where m and n are integers".
This sequence is included because one way to remove the assumption i <= 40 from A192110 (and the fifty other unproved sequences of the same type) would be to show that the complements are correct, using the method used to prove the correctness of A173671.

Crossrefs

Complement of A192110.

Extensions

Edited by N. J. A. Sloane, Oct 21 2019

A175832 Number of solutions of equation 3^q - 2^p = n over integer variables p, q.

Original entry on oeis.org

1, 2, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 0

Views

Author

Vladimir Reshetnikov, Sep 15 2010

Keywords

Comments

a(n)=0 iff n is in A173671; a(n)>0 iff n is in A192111.

Extensions

Edited and extended by Max Alekseyev, Jan 28 2012
Showing 1-4 of 4 results.