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.

A072686 Prime numbers whose (British) English names have a prime number of letters.

Original entry on oeis.org

2, 3, 7, 23, 37, 79, 83, 97, 109, 139, 157, 163, 167, 199, 211, 229, 239, 257, 263, 271, 313, 401, 421, 431, 449, 491, 503, 521, 569, 643, 647, 653, 709, 719, 751, 761, 809, 907, 991, 1021, 1031, 1049, 1069, 1091, 1103, 1301, 1303, 1307, 1327, 1409, 1511
Offset: 0

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 02 2002

Keywords

Comments

See A231075 for the American English version. The sequences coincide up to a(8)=97 but are then completely different, due to the additional "and" (e.g. in "one hundred and nine") in the British style. - M. F. Hasler, Nov 03 2013

Examples

			e.g. 2003 -> "TWOTHOUSANDANDTHREE" -> 19 letters and 19 is prime. Note that the "and" naming convention is used; e.g. "ONE HUNDRED AND ONE", "ONE THOUSAND NINE HUNDRED AND SEVENTY THREE".

Links

Crossrefs

Prime elements of A072685.

A119960 Positive integers with prime number of characters in their English names, including spaces and hyphens.

Original entry on oeis.org

1, 2, 3, 6, 7, 8, 10, 15, 16, 24, 25, 29, 34, 35, 39, 40, 43, 47, 48, 50, 53, 57, 58, 60, 63, 67, 68, 70, 71, 72, 73, 76, 77, 78, 84, 85, 89, 94, 95, 99
Offset: 1

Views

Author

Jonathan Vos Post, Aug 02 2006

Keywords

Comments

Differs due to hyphens and spaces from A072685 Positive integers whose English names contain a prime number of letters. Primes with prime number of characters in their English names, including spaces and hyphens, are a subset of this beginning: 2, 3, 7, 29, 43, 47, 53, 67, 71, 73.

Crossrefs

Cf. A000040, A052360, A005589, A052362-A052363, A072685.

Programs

  • Mathematica
    Select[Range[99], PrimeQ[ StringLength@ IntegerName[#, "Words"]] &] (* Giovanni Resta, Jun 13 2016 *)

Formula

n such that A052360(n) is prime. n such that A052360(n) is in A000040.

Extensions

Missing a(1) and more terms from Giovanni Resta, Jun 13 2016

A072688 Of the first n integers (inclusive), how many of them have a prime number of letters in their English names?

Original entry on oeis.org

1, 2, 3, 3, 3, 4, 5, 6, 6, 7, 7, 7, 7, 7, 8, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 11, 12, 12, 12, 12, 12, 13, 13, 13, 13, 14, 15, 15, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19
Offset: 1

Views

Author

Mark Hudson (mrmarkhudson(AT)hotmail.com), Jul 02 2002

Keywords

Examples

			Sequence A072685 begins: 1, 2, 3, 6, 7, 8, 10 so there are 3 terms up to and including n=4, 3 terms up to and including n=5, 6 terms up to and including n=9. Therefore a(4)=3, a(5)=3, a(9)=6.

Crossrefs

Cf. A072685, A072687.

Formula

a(n)=number of terms of A072685 <= n.

Extensions

a(17) onward corrected by Sean A. Irvine, Oct 20 2024

A151716 Positive integers whose Spanish names contain a prime number of letters.

Original entry on oeis.org

1, 2, 5, 7, 9, 13, 14, 25, 27, 29, 30, 31, 32, 35, 37, 39, 43, 46, 48, 51, 52, 60, 61, 62, 65, 67, 69, 70, 71, 72, 75, 77, 79, 80, 81, 82, 85, 87, 89, 90, 91, 92, 95, 97, 99, 105, 107, 109, 113, 114, 125, 127, 129, 130, 131, 132, 135, 137, 139, 143, 146, 148, 151, 152
Offset: 1

Views

Author

Claudio Meller, Jun 08 2009

Keywords

Comments

1 = uno (3 letters, 3 is prime); 7 = siete (5 letters, 5 is prime)

Crossrefs

Cf. A072685
Showing 1-4 of 4 results.

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