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.

A090055 Numbers n divisible by at least one nontrivial permutation (rearrangement) of the digits of n.

Original entry on oeis.org

105, 108, 405, 510, 540, 702, 703, 810, 1001, 1005, 1008, 1020, 1050, 1053, 1080, 2002, 2016, 2025, 2040, 2050, 2079, 2100, 2106, 3003, 3024, 3042, 3045, 3060, 3105, 3402, 3510, 4004, 4005, 4050, 4070, 4080, 4200, 5005, 5010, 5040
Offset: 1

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Author

Chuck Seggelin, Nov 21 2003

Keywords

Comments

Trivial permutations are identified as (1) permutation = n, or (2) when n mod 10=0, permutations of n's digits which result in shifting only trailing zeros to the most significant side of n where they drop off, such that permutation = n/10^z, where z <= the number of trailing zeros of n. So if n were 1809000, the following permutations would be excluded as trivial: 1809000, 0180900, 0018090, 0001809.
A031877 (numbers which are multiples of their reversals) and both A084687 and A090053 (numbers divided by number formed by sorting their digits), are subsets of this sequence. This sequence differentiates itself by including terms such as 7425 which is divided by 2475 (a rearrangement of 7425's digits that is neither a reversal or an ascending sort.)

Examples

			a(27)=3045 because 3045 is divisible by 435, a nontrivial permutation of 3045. (0435)
		

Crossrefs

A090061 Numbers k divisible by exactly two nontrivial permutations (rearrangements) of the digits of k, excluding all permutations that result in digit loss.

Original entry on oeis.org

571428, 867132, 874125, 923076, 5179428, 5714028, 5714280, 5714820, 5719428, 5971428, 8524710, 8571042, 8671320, 8679132, 8741250, 8749125, 8914752, 8957142, 9230760, 9239076, 37451268, 41957028, 42195708, 42713568, 42915780, 42971580, 43157286, 43751286, 48713562, 51374268
Offset: 1

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Author

Chuck Seggelin, Nov 21 2003

Keywords

Comments

Trivial permutations are identified as those where the permutation = k itself. Digit loss occurs when a permutation has 0 in the most significant position, which drops off, leaving a number with fewer digits. For example, when k is 3105, the permutation 0315 is excluded because 315 has fewer digits than 3105.
In the first million values of k, there is only one term that is divisible by three lossless nontrivial permutations. That term is 857142 which is divisible by 142857, 285714 and 428571. Note that 857142 is equal to floor((6/7)*10^6).

Examples

			a(4)=923076 is a term because 923076 is divisible by both 230769 and 307692, two nontrivial permutations of 923076 with the same number of digits.
		

Crossrefs

Programs

  • PARI
    \\ See Corneth link

Extensions

a(5)-a(25) from Donovan Johnson, Sep 16 2009
More terms from David A. Corneth, Jun 08 2025

A090058 Numbers n divisible by exactly three nontrivial permutations (rearrangements) of the digits of n.

Original entry on oeis.org

4050, 8100, 10500, 10530, 10800, 34020, 51000, 54000, 60912, 68040, 70300, 80190, 95040, 100100, 100500, 100800, 102000, 105030
Offset: 1

Views

Author

Chuck Seggelin, Nov 21 2003

Keywords

Comments

Trivial permutations are identified as (1) permutation = n, or (2) when n mod 10=0, permutations of n's digits which result in shifting only trailing zeros to the most significant side of n where they drop off, such that permutation = n/10^z, where z <= the number of trailing zeros of n. So if n were 1809000, the following permutations would be excluded as trivial: 1809000, 0180900, 0018090, 0001809.

Examples

			60912 is a term because 60912 is divisible by 1269, 1296 and 1692, three nontrivial permutations of 60912.
		

Crossrefs

A090059 Numbers n divisible by exactly four nontrivial permutations (rearrangements) of the digits of n.

Original entry on oeis.org

31050, 50490, 70200, 92070, 100035, 100980, 102060, 105000, 108000
Offset: 1

Views

Author

Chuck Seggelin, Nov 21 2003

Keywords

Comments

Trivial permutations are identified as (1) permutation = n, or (2) when n mod 10=0, permutations of n's digits which result in shifting only trailing zeros to the most significant side of n where they drop off, such that permutation = n/10^z, where z <= the number of trailing zeros of n. So if n were 1809000, the following permutations would be excluded as trivial: 1809000, 0180900, 0018090, 0001809.

Examples

			50490 is a term because 50490 is divisible by 459, 495, 594 and 4590, four nontrivial permutations of 50490.
		

Crossrefs

A090060 Numbers n divisible by exactly five nontrivial permutations (rearrangements) of the digits of n.

Original entry on oeis.org

40500, 81000, 98010, 105300
Offset: 1

Views

Author

Chuck Seggelin, Nov 21 2003

Keywords

Comments

Trivial permutations are identified as (1) permutation = n, or (2) when n mod 10=0, permutations of n's digits which result in shifting only trailing zeros to the most significant side of n where they drop off, such that permutation = n/10^z, where z <= the number of trailing zeros of n. So if n were 1809000, the following permutations would be excluded as trivial: 1809000, 0180900, 0018090, 0001809.

Examples

			98010 is a term because 98010 is divisible by 198, 891, 1089, 8910 and 10890, five nontrivial permutations of 98010.
		

Crossrefs

Showing 1-5 of 5 results.