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.

A226609 Irregular array read by rows. a(n) is the length of the primitive Collatz-like 3x+k cycle associated with A226607(n).

Original entry on oeis.org

2, 3, 5, 5, 27, 27, 4, 6, 14, 4, 24, 8, 8, 8, 8, 8, 8, 8, 7, 31, 11, 5, 5, 43, 16, 8, 5, 17, 65, 65, 23, 8, 8, 6, 6, 6, 20, 11, 18, 28, 7, 7, 7, 7, 7, 38, 29, 12, 6, 28, 28, 10, 10, 10, 10, 10, 10, 6, 66, 24, 30, 10, 10, 27, 27, 27, 27, 27, 12, 60, 15, 38
Offset: 1

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Author

Geoffrey H. Morley, Jun 13 2013

Keywords

Examples

			The irregular array starts:
(k=1)  2;
(k=5)  3, 5, 5, 27, 27;
(k=7)  4;
(k=11) 6, 14;
a(2)=3 is the length of the 3x+5 cycle {1,4,2} associated with A226607(2)=1.
		

Crossrefs

Row n begins with a(A226612(n)) and has length A226613(n).
The cycle associated with a(n) has A226610(n) odd elements of which A226608(n) is the largest.

A226688 Smallest positive integer in the primitive Collatz-like 3x-k cycle(s) with the conjectured record-breaking length A226686(n).

Original entry on oeis.org

17, 115, 2263, 113, 769, 436099, 6073, 3735185, 194197, 230891, 4575823, 823027, 21111517, 12477095
Offset: 1

Views

Author

Geoffrey H. Morley, Jun 16 2013

Keywords

Crossrefs

k = A226687(n).
Cf. A226672.

A226670 Record-breaking values, for increasing positive integers k == 1 or 5 mod 6, of the conjectured length of the longest primitive cycle(s) of positive integers under iteration by the Collatz-like 3x+k function.

Original entry on oeis.org

2, 27, 31, 43, 65, 66, 100, 106, 118, 136, 140, 141, 162, 200, 222, 262, 426, 476, 526, 636, 737, 1922, 2254, 4531, 4686, 5194, 5945, 9946, 10702, 14219, 16340, 19904, 37582, 40983, 49711, 63330
Offset: 1

Views

Author

Geoffrey H. Morley, Jun 16 2013

Keywords

Comments

A cycle is called primitive if its elements are not a common multiple of the elements of another cycle.
The 3x+k function T_k is defined by T_k(x) = x/2 if x is even, (3x+k)/2 if x is odd, where k is odd.
For primitive cycles, GCD(k,6)=1.

Crossrefs

k = A226671(n). The smallest integer in the T_k cycle(s) associated with a(n) is A226672(n).

Extensions

Definition clarified by Geoffrey H. Morley, Jun 23 2013

A226671 Integer k associated with the conjectured record-breaking length A226670(n) of primitive Collatz-like 3x+k cycles.

Original entry on oeis.org

1, 5, 17, 23, 29, 61, 85, 107, 125, 139, 143, 197, 253, 313, 371, 509, 563, 1135, 1163, 1307, 1699, 3299, 8431, 11491, 16819, 22097, 24917, 49787, 67475, 76733, 99391, 110273, 111611, 144379, 273641, 308219
Offset: 1

Views

Author

Geoffrey H. Morley, Jun 16 2013

Keywords

Crossrefs

Showing 1-4 of 4 results.