+- HP Forums (https://www.hpmuseum.org/forum)
+-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html)
+--- Forum: General Forum (/forum-4.html)
+--- Thread: a prime year (/thread-7502.html)
a prime year - Don Shepherd - 01-01-2017 06:12 PM
Welcome to 2017, a prime year!
When was the last prime year?
When will be the next prime year?
RE: a prime year - Massimo Gnerucci - 01-01-2017 07:05 PM
Also... 9² + 44² = 2017
RE: a prime year - Massimo Gnerucci - 01-01-2017 07:07 PM
(01-01-2017 06:12 PM)Don Shepherd Wrote: Welcome to 2017, a prime year!
When was the last prime year?
When will be the next prime year?
2011
2027
RE: a prime year - Don Shepherd - 01-01-2017 09:45 PM
(01-01-2017 07:07 PM)Massimo Gnerucci Wrote:(01-01-2017 06:12 PM)Don Shepherd Wrote: Welcome to 2017, a prime year!
When was the last prime year?
When will be the next prime year?
2011
2027
right!!
RE: a prime year - Gilles59 - 01-02-2017 09:23 AM
PREVPRIME LASTARG NEXTPRIME
RE: a prime year - Harald - 01-02-2017 02:17 PM
(01-01-2017 09:45 PM)Don Shepherd Wrote:(01-01-2017 07:07 PM)Massimo Gnerucci Wrote: 2011
2027
right!!
I'll vote for a "lastprime" function in the WP34s if you are going to ask more questions like that
RE: a prime year - Paul Dale - 01-02-2017 08:05 PM
(01-02-2017 02:17 PM)Harald Wrote: I'll vote for a "lastprime" function in the WP34s if you are going to ask more questions like that
The code is in XROM, just not included in any image:
Code:
XLBL"PREVPRIME"
INTM?
JMP prevprime_xin
DBL?
JMP prevprime_dbl
xIN MONADIC
_INT 50
_INT 16
10[^x]
STO+ Y
RCL Z
x>? Z
ERR ERR_DOMAIN
MIN
JMP prevprime_skip_xin
prevprime_dbl:: [infinity]?
ERR ERR_DOMAIN
prevprime_xin:: xIN MONADIC
prevprime_skip_xin:: CEIL
PRIME?
DEC X
x[<=]1?
ERR ERR_DOMAIN
EVEN?
prevprime_loop:: DEC X
x[<=]1?
JMP prime_2
PRIME?
xOUT xOUT_NORMAL
DEC X
JMP prevprime_loopIt would be easy enough to key this in as a user program.
Pauli
RE: a prime year - JMBaillard - 01-02-2017 10:58 PM
Happy New Year to everyone.
A few funny things about 2017:
2017 = 9^2+44^2
= 12^2+28^2+33^2
= 7^3+7^3+11^3
= 6^3+7^3+9^3+9^3
= 2^3+4^3+6^3+9^3+10^3
= 1^3+6^3+6^3+7^3+8^3+9^3 = ....
Best wishes,
JM.
RE: a prime year - Gerald H - 01-03-2017 05:59 AM
Puzzle from The Guardian:
https://www.theguardian.com/science/2017/jan/02/did-you-solve-it-new-year-new-number-new-equation
RE: a prime year - Eddie W. Shore - 01-04-2017 02:00 PM
Happy New Prime Year!
RE: a prime year - Gerald H - 01-07-2017 12:39 PM
While prime, not a perfect year:
https://oeis.org/A061013