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.

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A133794 Times on a 12-hour digital clock with all digits in {1, 2, 3, 4, 5, 6}.

Original entry on oeis.org

111, 112, 113, 114, 115, 116, 121, 122, 123, 124, 125, 126, 131, 132, 133, 134, 135, 136, 141, 142, 143, 144, 145, 146, 151, 152, 153, 154, 155, 156, 211, 212, 213, 214, 215, 216, 221, 222, 223, 224, 225, 226, 231, 232, 233, 234, 235, 236, 241, 242, 243
Offset: 1

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Author

Jonathan Vos Post, Jan 05 2008

Keywords

Comments

Digital clock dice integers. The number of values with 3 digits is 180. The number of values with 4 digits is 60. The number of values with 5 digits is 5400. The number of values with 6 digits is 1800. The total number of values is 7440, to the maximum 125656 equated to "12:56:56." Prime values must end with one of {11, 13, 21, 23, 31, 33, 41, 43, 51, 53}. The number of prime values with 3 digits is 23. The number of prime values with 4 digits is 6, namely 1123, 1151, 1153, 1213, 1223, 1231. Prime values with 5 digits begin 11113, 11131, 11213, 11243, 11251, 11257.

Examples

			"151" equated to "1:51"; "123456" equated to "12:34:56".
		

Crossrefs

Cf. A000040, A036960, A052382, A057436, A133783, index for "digital clock".

Programs

  • Maple
    c:=0: for h from 0 to 12 do for m from 0 to 59 do for s from 0 to 59 do t:=10000*h+100*m+s: d:=convert(t,base,10): if(t>100 and (h>0 or m<=12) and numboccur(d,0)=0 and numboccur(d,7)=0 and numboccur(d,8)=0 and numboccur(d,9)=0)then printf("%d, ", t): c:=c+1: fi: od: if(c>=80)then break: fi: od: od: # Nathaniel Johnston, May 17 2011
  • Mathematica
    FromDigits/@Flatten[Table[{h,m1,m2},{h,6},{m1,5},{m2,6}],2] (* Harvey P. Dale, Mar 13 2023 *)

Formula

A057436 INTERSECTION {integers that can appear on a 12-hour digital clock, concatenated from either hours:minutes or hours:minutes:seconds}.

Extensions

Comments corrected by Nathaniel Johnston, May 17 2011
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