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+--- Forum: General Software Library (/forum-13.html)
+--- Thread: (50G) Champernowne Sequence (OEIS A030190) (/thread-7536.html)
(50G) Champernowne Sequence (OEIS A030190) - Gerald H - 01-08-2017 09:35 AM
The Champernowne sequence
https://oeis.org/A030190
is the natural number sequence
https://en.wikipedia.org/wiki/ISO_80000-2
concatenated in binary & split into single digits:
0,1,1,0,1,1,1,0,0.........
For integer input N the programme returns the Nth element of the series starting from index zero.
Code:
::
CK1&Dispatch
BINT1
::
FPTR2 ^PUSHFLAGS_
%ABSCOERCE
#1+
DOBIN
BINT64
dostws
BINT0
BEGIN
DUP
#>HXS
hxs>$
LEN$
#2-
ROTSWAP
2DUP
#-
4UNROLL
DIFF_OR_ZERO_
#0<>
WHILE
#1+
REPEAT
#>HXS
hxs>$
BINT3
LAST$
DUPLEN$
FPTR2 ^POPFLAGS_
ROTSWAP
2DUP#>
IT
::
BINT0
ROT
#-SWAP
;
SWAP#-
DUP
SUB$
FPTR2 ^S>Z
;
;RE: HP 50g: Champernowne Sequence (OEIS A030190) - Gerald H - 01-17-2017 08:25 AM
An alternative algorithm is used in the programme below, having LAMBW as a sub-programme.
LAMBW returns the Lambert w function for real input & can be found here
http://www.hpmuseum.org/forum/thread-7616.html
I would be grateful for improvements to the programme & notification of any aberrant results.
Code:
CK1&Dispatch
BINT1
::
%2
%LN
%2
%/
OVER
%1-
%*
xLAMBW
%2
%LN
%/
%1+
%CEIL
%2
OVER
%^
DUP
4PICK
%+
%2
%-
3PICK
%MOD
3PICK
%-
%1+
%2
SWAP
%^
4UNROLL
ROT
%+
%1-
SWAP
%/
%1-
%CEIL
%*
%FLOOR
%2
%MOD
;
;