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 1-3 of 3 results.

A264965 Permutation of nonnegative integers: a(n) = A263273(A057889(n)).

Original entry on oeis.org

0, 1, 2, 3, 4, 7, 6, 5, 8, 9, 10, 13, 12, 19, 22, 21, 16, 25, 18, 17, 20, 15, 26, 55, 24, 11, 14, 27, 28, 23, 30, 37, 64, 57, 46, 43, 36, 67, 70, 33, 40, 31, 66, 79, 52, 63, 38, 47, 48, 73, 58, 75, 76, 49, 54, 65, 56, 39, 34, 29, 60, 61, 74, 45, 32, 59, 42, 145, 68, 81, 226, 193, 72, 35, 82, 219, 100, 217, 174, 121, 80, 69
Offset: 0

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Author

Antti Karttunen, Dec 05 2015

Keywords

Comments

Perform an adjusted reverse of n in base 2, followed by another adjusted reverse in base 3. "Adjusted reverse" here means the digit-reversing operation in which the tail of trailing zeros (in the base in question) is fixed, while the portion from the most significant digit to the least significant nonzero digit is reversed.
What percentage of the cycles are finite? (See the scatter-plot and A264969, also A264972, A264973.)

Crossrefs

Programs

Formula

a(n) = A263273(A057889(n)).
Other identities. For all n >= 0:
A000035(a(n)) = A000035(n). [This permutation preserves the parity of n.]

A264972 Trajectory of 262 under repeated application of the permutation A264965: a(0) = 262; for n >= 1, a(n) = A264965(a(n-1)).

Original entry on oeis.org

262, 670, 1450, 1690, 2158, 4246, 19522, 18410, 34678, 36926, 118882, 146998, 290566, 377966, 240038, 381466, 407054, 178898, 147146, 149714, 159458, 149378, 129242, 117958, 157822, 350014, 489878, 180770, 155930, 395686, 510386, 292426, 514294, 503114, 264490, 435670, 482882, 311674, 452774, 353570, 323374, 369638, 321926, 293726
Offset: 0

Views

Author

Antti Karttunen, Dec 06 2015

Keywords

Comments

The trajectory is probably infinite, not periodic.

Examples

			a(0) = 262 by definition. Its binary representation is A007088(262) = 100000110. When we reverse the significant prefix (i.e., leave the trailing zeros where they are), we get 386 (A007088(386) = 110000010). 386's ternary representation is A007089(386) = 112022. Reversing the significant prefix (now the whole expansion because no trailing zeros present), we get 220211 (= A007089(670)), thus a(1) = 670.
		

Crossrefs

Formula

a(0) = 262; for n >= 1, a(n) = A264965(a(n-1)).

A264973 Trajectory of 262 under permutation A264966: a(0) = 262; for n >= 1, a(n) = A264966(a(n-1)).

Original entry on oeis.org

262, 338, 850, 1058, 1238, 1838, 1786, 734, 1622, 1594, 710, 554, 818, 1118, 1574, 2014, 1834, 1306, 742, 1922, 1270, 838, 1018, 718, 334, 290, 802, 622, 322, 494, 650, 478, 266, 946, 550, 274, 458, 922, 766, 790, 1778, 1054, 826, 1418, 1358, 1982, 1606, 1954, 614, 674, 794, 1478, 1702, 986, 1526, 1870, 1714, 1090, 598, 298, 386, 970, 1370
Offset: 0

Views

Author

Antti Karttunen, Dec 06 2015

Keywords

Comments

The trajectory is probably infinite, not periodic.

Examples

			a(0) = 262 by definition. Its base-3 representation is A007089(262) = 100201. Reversing the significant prefix (in this case the whole expansion because no trailing zeros present), we get 102001 (= A007089(298)). Base-2 representation of 298 is 100101010 (= A007088(298)). Reversing its significant prefix, we get 101010010 (= A007088(338)), thus a(1) = 338.
		

Crossrefs

Formula

a(0) = 262; for n >= 1, a(n) = A264966(a(n-1)).
Showing 1-3 of 3 results.