

A289742


Sizes of wrenches (or spanners) using imperial units.


0



1, 4, 5, 16, 3, 8, 7, 16, 1, 2, 9, 16, 5, 8, 11, 16, 3, 4, 13, 16, 7, 8, 15, 16, 1, 1, 17, 16, 9, 8, 19, 16, 5, 4, 21, 16, 11, 8, 23, 16, 3, 2, 25, 16, 13, 8, 27, 16, 7, 4, 29, 16, 15, 8, 31, 16, 2, 1, 33, 16, 17, 8, 35, 16, 9, 4, 37, 16, 19, 8, 39, 16, 5, 2
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OFFSET

1,2


COMMENTS

Found on sets of wrenches (US) or spanners (UK) for nut sizes in imperial units. List gives pairs (numerator, denominator) for the reduced fractions that specify the sizes.


LINKS



FORMULA

The sizes, which come in integer multiples of 1/16 inch, are equal to 4/16", 5/16", 6/16", ... but as it is customary to reduce fractions, these sizes are embossed on the wrenches as 1/4, 5/16, 3/8, .... This reduction leads to a set of numbers that are not as simple as those on metric wrenches (where the sequence is simply 6mm, 7mm, 8mm, 9mm, ...) and can make it more difficult to find the next larger or smaller wrench if the current one does not fit. So far nobody has ever been able to find the next number when I give the first 7 terms. It is similar in fun value to the clock chiming sequence A007879.


EXAMPLE

The fractions are 1/4, 5/16, 3/8, 7/16, 1/2, etc.


MATHEMATICA

{Numerator[#], Denominator[#]}&/@NestList[#+1/16&, 1/4, 50]//Flatten (* Harvey P. Dale, Oct 13 2018 *)


CROSSREFS



KEYWORD

nonn,dumb,fini


AUTHOR



EXTENSIONS



STATUS

approved



