a prime year

[Don Shepherd]

Welcome to 2017, a prime year!

When was the last prime year?

When will be the next prime year?

[Massimo Gnerucci]

Also... 9² + 44² = 2017

[Massimo Gnerucci]

(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

[Don Shepherd]

(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!!

[Gilles59]

PREVPRIME LASTARG NEXTPRIME

[Harald]

(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

[Paul Dale]

(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_loop

It would be easy enough to key this in as a user program.


Pauli

[JMBaillard]

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.

[Gerald H]

Puzzle from The Guardian:

https://www.theguardian.com/science/2017...w-equation

[Eddie W. Shore]

Happy New Prime Year!

[Gerald H]

While prime, not a perfect year:

https://oeis.org/A061013