OFFSET
1,1
COMMENTS
Benjamin Franklin, first Postmaster General of the United States, applied computational complexity theory to Economics by changing the business plan for American mail by changing from payment by distance to payment by weight. "Before stamps were used a person had to collect his mail at the post office and pay for it. Franklin stopped the money loss on unclaimed mail in Philadelphia by printing in his paper the names of persons who had mail awaiting them. He also developed a simple, accurate way of keeping post-office accounts. In 1753 Franklin was made deputy postmaster general for all the colonies." [Encyclopedia Britannica]
REFERENCES
R. K. Guy, Unsolved Problems in Number Theory, C12.
LINKS
R. Alter and J. A. Barnett, A postage stamp problem, Amer. Math. Monthly, Vol. 87, No. 3 (1980), 206-210.
W. F. Lunnon, A postage stamp problem, Comput. J., Vol. 12, No. 4 (1969) 377-380.
1847usa.com, United States Postage Stamps By Year.
EXAMPLE
a(1) = -2 because the rate per half ounce was lowered effective 3 March 1863 from 3 cents to 2 cents; thereafter rates were per ounce.
CROSSREFS
KEYWORD
easy,fini,sign
AUTHOR
Jonathan Vos Post, Feb 03 2006
STATUS
approved