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Edit 2022-12-11: Programme slightly improved

For integer input N > -1 the programme returns the Nth element in the sequence

https://oeis.org/A035327

Not a masterpiece but does use ←A.

Code:

«

  « DUP 2 <

    IF

    THEN 1 

    ELSE 2 IDIV2

SWAP ←A EVAL 2 * 1

+

    END SWAP -

  » → ←A

  « ←A EVAL

  »

»

Improvements welcome.

Hi Gerald

Nice to see you posting sequences again. Thanks especially for posting a program using compiled local variables, which still make my head spin. Studying your program may help. Smile

While I certainly can't improve on your program, I do have one from a completely different angle, based on the structure of the sequence. Given an integer n, this program returns a list of the first 2^(n+1) terms. So for example, given the number 5 the program will return the first 64 terms.

This program also uses the ListExt command LSEQR.

Code:

\<< 1 { 1 0 } ROT 1 SWAP

  START SWAP 2 * SWAP OVER 1 - 0 LSEQR +

  NEXT NIP

\>>

Gerald H

John Keith