The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A224950 Leap years having 53 Fridays and Saturdays. 0
 1588, 1616, 1644, 1672, 1712, 1740, 1768, 1796, 1808, 1836, 1864, 1892, 1904, 1932, 1960, 1988, 2016, 2044, 2072, 2112, 2140, 2168, 2196, 2208, 2236, 2264, 2292, 2304, 2332, 2360, 2388, 2416, 2444, 2472, 2512, 2540, 2568, 2596, 2608, 2636, 2664, 2692, 2704, 2732, 2760, 2788 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Gregorian calendar repeats after every 400 years because number of days in 400 years is 146097 which is a multiple of 7. Non-century years are leap years if and only if they are multiples of 4 while century years are leap years if and only if they are multiples of 400. 15 occurrences in 400 years. Months having Friday the 13th: May. February 29th falls on Monday. 366 day leap year: 52 Sundays, 52 Mondays, 52 Tuesdays, 52 Wednesdays, 52 Thursdays, 53 Fridays, 53 Saturdays. LINKS Time and Date, The Gregorian calendar Time and Date, 2016 Wikipedia, Gregorian calendar MATHEMATICA Select[Range[1583, 2800], DayOfWeek[{#, 1, 1}, Calendar -> Gregorian] == Friday && DaysBetween[{#, 1, 1}, {# + 1, 1, 1}, Calendar -> Gregorian] == 366 &, 50] (* T. D. Noe, Apr 22 2013 *) ly53Q[y_]:=LeapYearQ[{y}]&&Count[DayRange[{y, 1, 1}, {y, 12, 31}], _?(DayName[ #]==Friday&)]==53&&Count[DayRange[{y, 1, 1}, {y, 12, 31}], _?(DayName[#] == Saturday&)] ==53; Select[Range[1570, 2800], ly53Q] (* Harvey P. Dale, Oct 14 2021 *) CROSSREFS Sequence in context: A224941 A213116 A224942 * A233378 A083631 A224938 Adjacent sequences:  A224947 A224948 A224949 * A224951 A224952 A224953 KEYWORD nonn AUTHOR Aswini Vaidyanathan, Apr 21 2013 STATUS approved

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

Last modified June 26 20:01 EDT 2022. Contains 354885 sequences. (Running on oeis4.)