Mersenne Prime
Message #1 Posted by Gerson W. Barbosa on 6 Oct 2013, 9:41 p.m.
MP:
%%HP: T(3)A(R)F(.);
\<< DUP LN DUP \pi * 4 SWAP / 1 + UNROT / * IP 2 { 2 } ROT 2 SWAP
START SWAP NEXTPRIME DUP UNROT DUP 2 SWAP ^ 1 - 4 PICK3 2 - 1 SWAP
START SQ 2 - OVER MOD
NEXT NIP NOT { + } { DROP } IFTE
NEXT NIP
\>>
110 MP --> { 2 3 5 7 13 17 19 31 61 89 107 } ( 50 s, HP 50g )
607 MP --> { 2 3 5 7 13 17 19 31 61 89 107 127 521 607 } (250 s, Emulator)
References:
1) Mersenne Prime
2) Lucas–Lehmer primality test
P.S.: Version using local variables, for clarity
%%HP: T(3)A(R)F(.);
\<< DUP LN DUP \pi * 4 SWAP / 1 + UNROT / * IP 2 { 2 } ROT 2 SWAP
START SWAP NEXTPRIME DUP 2 SWAP ^ 1 - 4 \-> p m s
\<< 1 p 2 -
START s SQ 2 - m MOD 's' STO
NEXT p DUP UNROT s NOT { + } { DROP } IFTE
\>>
NEXT NIP
\>>
Edited: 6 Oct 2013, 10:43 p.m.
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