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.

A109733 Sequence is its own base-10 ASCII representation.

Original entry on oeis.org

53, 51, 53, 49, 53, 51, 52, 57, 53, 51, 53, 49, 53, 50, 53, 55, 53, 51, 53, 49, 53, 51, 52, 57, 53, 51, 53, 48, 53, 51, 53, 53, 53, 51, 53, 49, 53, 51, 52, 57, 53, 51, 53, 49, 53, 50, 53, 55, 53, 51, 53, 49, 53, 51, 52, 56, 53, 51, 53, 49, 53, 51, 53, 51, 53, 51, 53, 49, 53
Offset: 1

Views

Author

N. J. A. Sloane and Nadia Heninger, Aug 10 2005

Keywords

Comments

Out of the digits 0,1,...,9, 5 is the only one whose ASCII representation, converted to base 10, begins with itself. So this sequence is the unique one with this property. - N. J. A. Sloane, Aug 25 2015
The octal version of this idea is simply 66,66,66,66,.., not interesting.

Examples

			We use the following table, giving digit d, ASCII equivalent in base 8, ASCII equivalent in base 10:
  .0..1..2..3..4..5..6..7..8..9
  60 61 62 63 64 65 66 67 70 71
  48 49 50 51 52 53 54 55 56 57
We must start with 5 (see comment above), so the sequence grows like this:
  5
  53
  53 51
  53 51 53 49
  53 51 53 49 53 51 52 57
  ...
		

Crossrefs

See A109648 for another version.

Programs

  • PARI
    a(n) = (valuation(1+n>>n=valuation(n,2),2)%5!=3)+56-(n-3)%5*2  \\ M. F. Hasler, Jun 20 2011

Formula

I conjecture that a(n) = 53 when n is congruent to 1, 3 or 5 (mod 8) and a(n) = 51 when n is congruent to 2 (mod 8). - Jonathan Cross (jcross(AT)juggler.net), Oct 14 2005
a(n) = (if valuation(n/2^v + 1, 2) mod 5 = 3 then 56 else 57) - 2*((v-3) mod 5), where v = valuation(n,2), i.e., n = (2s+1)*2^v. (Translation of my PARI code from June 2011.) - M. F. Hasler, Feb 02 2016

Extensions

More terms from Jonathan Cross (jcross(AT)juggler.net), Oct 14 2005

A130764 ASCII codes for upper case letters.

Original entry on oeis.org

65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90
Offset: 1

Views

Author

Omar E. Pol, Aug 17 2007

Keywords

Comments

ASCII: American Standard Code for Information Interchange.

Examples

			A is code 65, B is code 66, Z is code 90.
		

Crossrefs

Programs

  • Mathematica
    ToCharacterCode[CharacterRange["A","Z"]]//Flatten (* Harvey P. Dale, Oct 02 2022 *)

Formula

a(n)=64+n, 0

A130765 ASCII codes for lower case letters.

Original entry on oeis.org

97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122
Offset: 1

Author

Omar E. Pol, Aug 17 2007

Comments

ASCII: American Standard Code for Information Interchange.

Examples

			b is code 98, z is code 122.
		

Crossrefs

Formula

a(n) = 96 + n, 0 < n < 27.
Showing 1-3 of 3 results.