OFFSET
1,1
COMMENTS
The index is 0-based, so 0 = Sunday, 1 = Monday, 2 = Tuesday, 3 = Wednesday, 4 = Thursday, 5 = Friday, 6 = Saturday.
The first term in the sequence represents the day of the week index for January 1, A.D. 2000.
The sequence repeats after 4800 terms, representing 400 years in the Gregorian calendar system.
REFERENCES
Arthur Benjamin and Michael Shermer, Secrets of Mental Math, First Edition, Three Rivers Press, 2006, p. 215.
LINKS
FORMULA
a(n+1) = (a(n) + A178055(n)) (mod 7).
EXAMPLE
a(1) = 6, so day of week for January 1, 2000 is Saturday; a(2) = 2, so day of week for February 1, 2000 is Tuesday; a(3) = 3, so day of week for March 1, 2000 is Wednesday.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Lyle P. Blosser (lyleblosser(AT)att.net), May 18 2010
STATUS
approved