login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A127376 Perpetual calendar, giving the calendar for successive years of the 400-year cycle starting in year xy01, where xy is a 2-digit multiple of 4. Calendars 1 to 7 are for normal years starting on Monday, Tuesday, ..., Sunday; 8 to 14 are for leap years likewise. 1
1, 2, 3, 11, 6, 7, 1, 9, 4, 5, 6, 14, 2, 3, 4, 12, 7, 1, 2, 10, 5, 6, 7, 8, 3, 4, 5, 13, 1, 2, 3, 11, 6, 7, 1, 9, 4, 5, 6, 14, 2, 3, 4, 12, 7, 1, 2, 10, 5, 6, 7, 8, 3, 4, 5, 13, 1, 2, 3, 11, 6, 7, 1, 9, 4, 5, 6, 14, 2, 3, 4, 12, 7, 1, 2, 10, 5, 6, 7, 8, 3, 4, 5, 13, 1, 2, 3, 11, 6, 7, 1, 9, 4, 5, 6, 14, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A090651 gives the 14-year repeating cycle applying between century years not a multiple of 400; this sequence extends that to the complete 400-year cycle.

LINKS

Ian Duff, Table of n, a(n) for n = 1..400

Index entries for sequences related to calendars

Index entries for linear recurrences with constant coefficients, order 400.

EXAMPLE

2001 is an ordinary year starting on a Monday, as a(1)=1; 2004 is a leap year starting on a Thursday, as a(4)=11; 2400 is a leap year starting on Saturday, as a(400)=13.

PROG

a(0)=13

for n=1 to 400

if (n mod 4 =0 and n mod 100 <>0) or n mod 400 =0 then

a(n)=a(n-1)+8 : if a(n)>14 then a(n)=a(n)-7

else

if (n-1 mod 4 =0 and n-1 mod 100 <>0) or n-1 mod 400 =0 then

a(n)=a(n-1)-5

else

a(n)=a(n-1)+1

end if

if a(n)>7 then a(n)=a(n)-7

end if

next n

CROSSREFS

Cf. A090651.

Sequence in context: A084047 A282770 A145077 * A086146 A083758 A127494

Adjacent sequences:  A127373 A127374 A127375 * A127377 A127378 A127379

KEYWORD

easy,nonn

AUTHOR

Ian Duff, Mar 30 2007

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 15 17:03 EST 2019. Contains 330000 sequences. (Running on oeis4.)