For values not covered by one of these C formulae, the order is incremented by an integer so that one C of these formulae apply.
Backward recursion is used to reduce C orders by integer values.
Leading terms of these expansions are used to test C for over or underflow where appropriate. If a sequence is C requested and the last member would underflow, the result is C set to zero and the next lower order tried, etc. An overflow C cannot occur with scaling. The maximum number of significant digits obtainable C is the smaller of 14 and the number of digits carried in C double precision arithmetic. C F. W. J. Olver, Tables of Bessel Functions of Moderate C or Large Orders, NPL Mathematical Tables 6, Her C Majesty's Stationery Office, London, 1962.