Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A131773
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A131773 Epact in Julian calendar for a year n with Golden Number (n mod 19) + 1 = A074805(n). +0
1
30, 11, 22, 3, 14, 25, 6, 17, 28, 9, 20, 1, 12, 23, 4, 15, 26, 7, 18, 30, 11, 22, 3, 14, 25, 6, 17, 28, 9, 20, 1, 12, 23, 4, 15, 26, 7, 18, 30, 11, 22, 3, 14, 25, 6, 17, 28, 9, 20, 1, 12, 23, 4, 15, 26, 7, 18, 30, 11, 22, 3, 14, 25, 6, 17, 28, 9, 20, 1, 12, 23, 4, 15, 26, 7, 18, 30, 11 (list; graph; listen)
OFFSET

0,1

COMMENT

Periodic with period 19 as there are 19 Golden Numbers. Basis for calculating Gregorian Epact. See sections about Epacts, Golden Numbers, and discussion of the 19-year Metonic cycle (in Chapter 1) of the Calendar FAQ link. The FAQ also discusses in detail in which years the different calendars have been adopted by different countries and that there was no year 0 (unless considering, say, a "proleptic" Gregorian calendar) -- so the first term here (and in A074805) is actually for 1 BC (1 BCE) of the Julian calendar.

LINKS

Claus Tondering, Frequently Asked Questions about Calendars.

FORMULA

a(n) = (11*(A074805(n)-1)) mod 30, but replacing every 0 result with 30. See program and link.

EXAMPLE

a(2007)=12 as the Julian Epact for the year 2007 is (11*(2007 mod 19)) mod 30 = (11*12) mod 30 = 12. ((2007 mod 19)+1 = 12+1 = 13 = A074805(2007) is the corresponding Golden Number for 2007).

PROGRAM

(PARI) a(n)= JE=(11*(n%19))%30; if(JE==0, 30, JE)

CROSSREFS

Cf. A074805.

Sequence in context: A040876 A073401 A040875 this_sequence A091746 A040874 A033350

Adjacent sequences: A131770 A131771 A131772 this_sequence A131774 A131775 A131776

KEYWORD

nonn

AUTHOR

Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 14 2007

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified August 19 23:53 EDT 2008. Contains 142930 sequences.


AT&T Labs Research