A011763 Days in year in proleptic Gregorian calendar.

365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366, 365, 365, 365, 366

Offset: 1

Author

Juan-Carlos Lerman (jclerm(AT)aztec.asu.edu)

Keywords

• nonn
• easy

Comments

This sequence is periodic with period 400. The exceptions to the apparent period 4 are a(100) = a(200) = a(300) = 365. - Franklin T. Adams-Watters, Jul 10 2009

Links

• Index entries for sequences related to calendars
• Index entries for linear recurrences with constant coefficients, order 400.

Programs

Mathematica

(* first do *) Needs["Calendar`"] (* then *) Table[ DaysBetween[{y, 1, 1}, {y + 1, 1, 1}], {y, 48}] (* Robert G. Wilson v, Apr 18 2010 *)

PARI

a(n)=if(n%4, 365, if(n%100, 366, n%400, 366, 365)) \\ Charles R Greathouse IV, Oct 13 2022