perl -MData::IEEE754::Tools=:all -e"printf qq(%-3d %-32.32s 0x%-16s %.16f %s\n), $_, 1+1/2**$_, hexstr754_from_double(1+1/2**$_), 1+1/2**$_, to_dec_floatingpoint(1+1/2**$_) for @ARGV" 47 48 49 50 51 52 53 54 55 56

47  1.00000000000001                 0x3FF0000000000020 1.0000000000000071 +0d1.0000000000000071p+0000
48  1                                0x3FF0000000000010 1.0000000000000036 +0d1.0000000000000036p+0000
49  1                                0x3FF0000000000008 1.0000000000000018 +0d1.0000000000000018p+0000
50  1                                0x3FF0000000000004 1.0000000000000009 +0d1.0000000000000009p+0000
51  1                                0x3FF0000000000002 1.0000000000000004 +0d1.0000000000000004p+0000
52  1                                0x3FF0000000000001 1.0000000000000002 +0d1.0000000000000002p+0000
53  1                                0x3FF0000000000000 1.0000000000000000 +0d1.0000000000000000p+0000
54  1                                0x3FF0000000000000 1.0000000000000000 +0d1.0000000000000000p+0000
55  1                                0x3FF0000000000000 1.0000000000000000 +0d1.0000000000000000p+0000
56  1                                0x3FF0000000000000 1.0000000000000000 +0d1.0000000000000000p+0000