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.

A116453 Third smallest number with exactly n prime factors.

Original entry on oeis.org

5, 9, 18, 36, 72, 144, 288, 576, 1152, 2304, 4608, 9216, 18432, 36864, 73728, 147456, 294912, 589824, 1179648, 2359296, 4718592, 9437184, 18874368, 37748736, 75497472, 150994944, 301989888, 603979776, 1207959552, 2415919104
Offset: 1

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Author

Reinhard Zumkeller, Feb 16 2006

Keywords

Comments

Smallest term in A116451 having exactly n prime factors;
a(n) = A116451(A116454(n)) = A116454(n) + 2 * n + 3;
a(n) = A005010(n-2) = 9*2^(n - 2) for n > 1.

Examples

			a(1) =  5 = A000040(3) > A000040(2) =  3 > A000040(1) =  2;
a(2) =  9 = A001358(3) > A001358(2) =  6 > A001358(1) =  4;
a(3) = 18 = A014612(3) > A014612(2) = 12 > A014612(1) =  8;
a(4) = 36 = A014613(3) > A014613(2) = 24 > A014613(1) = 16.

Links

Programs

A116451 Numbers having fewer prime factors than at least one smaller number.

Original entry on oeis.org

5, 7, 9, 10, 11, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 16 2006

Keywords

Comments

Complement of A029744.
Numbers whose odd part is greater than 3. - Peter Munn, Aug 12 2020

Crossrefs

Cf. A029744, A116452, A001222.

Formula

A116452(n) = A001222(a(n)).

Extensions

The offset should really be 1, since this is a list, but that change would also require a complete rewrite of A116454, plus changes to A116453. So for the moment let's leave this with offset 0. - N. J. A. Sloane, Aug 17 2020

A116452 Number of prime factors of A116451.

Original entry on oeis.org

1, 1, 2, 2, 1, 1, 2, 2, 1, 3, 1, 3, 2, 2, 1, 2, 2, 3, 3, 1, 3, 1, 2, 2, 2, 4, 1, 2, 2, 4, 1, 3, 1, 3, 3, 2, 1, 2, 3, 2, 3, 1, 4, 2, 4, 2, 2, 1, 4, 1, 2, 3, 2, 3, 1, 3, 2, 3, 1, 5, 1, 2, 3, 3, 2, 3, 1, 5, 4, 2, 1, 4, 2, 2, 2, 4, 1, 4, 2, 3, 2, 2, 2, 1, 3, 3, 4, 1, 3, 1, 4, 3, 2, 1, 5, 1, 3, 2, 5, 1, 3, 2, 3, 3, 2
Offset: 0

Views

Author

Reinhard Zumkeller, Feb 16 2006

Keywords

Comments

a(n) = A001222(A116451(n));
record values: A116453(n) = a(A116454(n)).
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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