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.

Previous Showing 11-16 of 16 results.

A139254 Primes that are not toothpick primes.

Original entry on oeis.org

2, 5, 13, 17, 19, 29, 31, 37, 41, 53, 59, 61, 71, 73, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191
Offset: 1

Views

Author

Omar E. Pol, May 11 2008

Keywords

Comments

Primes that are not members of A139253.

Crossrefs

A152768 Records in A139251.

Original entry on oeis.org

1, 2, 4, 8, 12, 16, 28, 32, 36, 40, 60, 88, 92, 112, 140, 208, 256, 260, 296, 364, 488, 672, 704, 708, 744, 956, 1216, 1648, 2048, 2052, 2096, 2108, 2396, 3128, 4080, 5344, 5952, 5956, 6000, 6300, 7920, 10336, 13504, 16640, 16644, 16688, 16696, 16988, 17100, 18612, 20040
Offset: 1

Views

Author

Omar E. Pol, Dec 15 2008, Dec 20 2008

Keywords

Comments

Excluding the initial 1 and 2, this sequence also gives the records in A147646. - Nathaniel Johnston, Apr 10 2011

Crossrefs

Cf. A139251, A139252, A139560. Toothpick sequence: A139250.
Cf. A052184.

Extensions

a(18) - a(51) from Nathaniel Johnston, Apr 10 2011

A152973 Records in A152968.

Original entry on oeis.org

1, 2, 4, 6, 8, 14, 16, 18, 20, 30, 44, 46, 56, 70, 104, 128, 130, 148, 182, 244, 336, 352, 354, 372, 478, 608, 824, 1024, 1026, 1048, 1054, 1198, 1564, 2040, 2672, 2976, 2978, 3000, 3150, 3960, 5168, 6752, 8320, 8322, 8344, 8348, 8494, 8550, 9306
Offset: 1

Views

Author

Omar E. Pol, Dec 16 2008

Keywords

Comments

Excluding the initial 1, this sequence also gives the records in A151688. - Nathaniel Johnston, Apr 10 2011

Crossrefs

Toothpick structure: A139250.
Cf. A152978.

Extensions

More terms from Omar E. Pol, Dec 20 2008
a(17)-a(49) from Nathaniel Johnston, Apr 10 2011

A139255 Complement of toothpick sequence A139250.

Original entry on oeis.org

2, 4, 5, 6, 8, 9, 10, 12, 13, 14, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 36, 37, 38, 39, 40, 41, 42, 44, 45, 46, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 69, 70, 71, 72
Offset: 1

Views

Author

Omar E. Pol, May 11 2008, Jan 02 2009

Keywords

Crossrefs

A210985 Number of segments needed to draw the toothpick structure of A139250 as it is after 2^n stages.

Original entry on oeis.org

1, 3, 7, 19, 63, 235, 919, 3651, 14575
Offset: 0

Views

Author

Omar E. Pol, Sep 11 2012

Keywords

Comments

It appears that this is also the partial sums of A039301.
It appears that this is also 1 together with A160128.

Examples

			For n = 3, after 2^3 stages the toothpick structure of A139250 contains 43 toothpicks (A139250(2^3) = 43). However the toothpick structure can be essentially represented by 19 segments (A139252(2^3) = 19), so a(3) = 19.
		

Crossrefs

Formula

a(n) = A139252(2^n).

A168115 a(n) = A139560(n+1)/2.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 1, 2, 2, 2, 4, 6, 4, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16, 8, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16, 8, 2, 4, 6, 6, 8, 14, 16, 10, 8, 14, 18, 20, 30, 44, 40, 16, 1, 1, 2, 2, 2, 4, 6, 4, 2, 4, 6, 6, 8, 14, 16
Offset: 1

Views

Author

Omar E. Pol, Dec 09 2009

Keywords

Crossrefs

Extensions

Terms after a(27) from Nathaniel Johnston, Mar 29 2011
Previous Showing 11-16 of 16 results.