OFFSET
1,1
COMMENTS
From Rick L. Shepherd, Mar 09 2009: (Start)
Easter can never occur in March in two consecutive years. (See the Tondering link for information that was helpful in confirming this; especially, 2.13.9 "Is there a simple relationship between two consecutive Easters?" My (OpenOffice.org Calc BASIC) program found that the X-8 and X-9 cases mentioned there never occurred when beginning with Mar. 30th or Mar. 31st the first year.) However, Easter can occur in April in exactly 1, 2, 4, 5, 7, 8, or 10 consecutive years (as seen by examining the entire 5700000-year Gregorian Easter cycle). The first year such that 10 consecutive years have the value 4 is 2856.
The <range> in the OpenOffice.org Calc spreadsheet array formula below is set to reference a set of cells containing the years of interest (Edit>Fill>Series Linear is useful for autofilling). The EASTERSUNDAY function is documented as accepting years from 1583 to 9956.
(A156743 as originally written (and extended here) should have offset 1901.) (End)
LINKS
Claus Tondering, Frequently Asked Questions about Calendars. [From Rick L. Shepherd, Mar 09 2009]
EXAMPLE
a(1902)=3 because Easter in 1902 was in March.
MATHEMATICA
Needs["Calendar`"]; Table[ EasterSunday[year], {year, 1901, 2012}][[All, 2]] (* Jean-François Alcover, Sep 26 2011 *)
PROG
(Other) OpenOffice.org Calc {=MONTH(EASTERSUNDAY(<range>))} [From Rick L. Shepherd, Mar 09 2009]
CROSSREFS
KEYWORD
nonn
AUTHOR
J. Lowell, Feb 14 2009
EXTENSIONS
Extended by Rick L. Shepherd, Mar 09 2009
Minor edits by Jon E. Schoenfield, Feb 19 2014
STATUS
approved