A141287 Years in which there are five Fridays in the month of February.

1760, 1788, 1828, 1856, 1884, 1924, 1952, 1980, 2008, 2036, 2064, 2092, 2104, 2132, 2160, 2188, 2228, 2256, 2284, 2324, 2352, 2380, 2408, 2436, 2464, 2492, 2504, 2532, 2560, 2588, 2628, 2656, 2684, 2724, 2752, 2780, 2808, 2836, 2864, 2892, 2904, 2932

Offset

1,1

Links

Table of n, a(n) for n=1..42.

Index entries for sequences related to calendars

Index entries for linear recurrences with constant coefficients, signature (1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1).

Maple

A141287 := proc(n) nper := (n-1) mod 14 ; floor((n-1)/14)*400+op(1+nper , [1760, 1788, 1828, 1856, 1884, 1924, 1952, 1980, 2008, 2036, 2064, 2092, 2104, 2132]) ; end proc: seq(A141287(n), n=1..80) ; # R. J. Mathar, Jan 25 2010

Mathematica

(* First do *) Needs["Calendar`"] (* then *) fQ[y_] := Mod[y, 4] == 0 && Mod[y, 400]!=0 && DayOfWeek[{y, 2, 1}] == Friday; Select[Range[1750, 3051], fQ@# &] (* Robert G. Wilson v, Jun 11 2010 *)
(* Second program, needing Mma version >= 9.0 *)
okQ[y_] := Mod[y, 4] == 0 && DayCount[{y, 1, 31}, DatePlus[{y, 3, 1}, -1], Friday] == 5;
Select[Range[1752, 3051, 4], okQ] (* Jean-François Alcover, Mar 27 2020 *)

Crossrefs

Cf. A119406 (Sun), A135795 (Mon), A143994 (Tue), A141039 (Wed), A143995 (Thu), A176478 (Sat).

Sequence in context: A186012 A031802 A020419 * A238050 A213804 A252309

Adjacent sequences: A141284 A141285 A141286 * A141288 A141289 A141290

Keyword

nonn

Author

J. Lowell, Aug 01 2008

Extensions

More terms using the 400-year periodicity of the Gregorian calendar by R. J. Mathar, Jan 25 2010

Status

approved