(49G) OEIS A131421: (A000012 * A127775) + (A127775 * A000012) - A000012

[Gerald H]

For natural number input N the programme returns the Nth element of the sequence

https://oeis.org/A131421

where you'll notice that the description of the sequence

(A000012 * A127775) + (A127775 * A000012) - A000012

indicates that the author's descriptive powers failed her, although she clearly maintained a sense of humour.

Any more refined attempts at verbally describing the sequence?

I recommend you replace

FPTR2 ^ZSQRT

with

http://www.hpmuseum.org/forum/thread-3837.html

as the built in function errs for larger input & is also slower.

Size: 180.5

CkSum: # 9E6Eh

Code:

::
  CK1&Dispatch
  # FF
  ::
    ZINT 0
    ZINT 0
    ROTDUP
    FPTR2 ^ZSQRT
    DROP
    DUP
    ZINT 4
    FPTR2 ^ZQUOText
    FPTR2 ^RADDext
    BEGIN
    ZINT 1
    FPTR2 ^RADDext
    DUPDUP
    DUP
    FPTR2 ^RMULText
    FPTR2 ^SWAPRSUB
    ZINT 2
    FPTR2 ^ZQUOText
    ZINT 1
    FPTR2 ^RADDext
    DUP
    4PICK
    Z<=
    WHILE
    ::
      5ROLLDROP
      4ROLLDROP
      OVER
      4UNROLL
      4UNROLL
    ;
    REPEAT
    2DROP
    FPTR2 ^RADDext
    FPTR2 ^SWAPRSUB
    DUP
    FPTR2 ^RADDext
    ZINT 1
    FPTR2 ^RSUBext
  ;
;