Prime Number - Page 12

[valerium]

Another relatively big jump to 1973, a good year for a hot summer :-)

[valerium]

And then to 1979, I turned 16 and my first Gary Numan gig in Glasgow. Oh to be 16 again (err.. maybe not!)

[BearofNH]

1987

The market crashed and I painfully realized that what goes up must come down. Things are no different these days.

[jasimp]

1993

[BearofNH]

1999

The smallest prime number such that the sum of its digits is a perfect number.

[jasimp]

BearofNH this is how it goes 1993 --> 1997 --> 1999

[valerium]

Ahh 2003.

Turned 40 and wondered where it had all gone!

[BearofNH]

2011

The next prime year.

(Oops, how could I miss 1997? I must have been lost in a fog.)

[jasimp]

2017

[scudzilla]

1987

The market crashed and I painfully realized that what goes up must come down. Things are no different these days.

The year I was born.

Next: 2027 in which I will turn 40

[jasimp]

2029

[scudzilla]

2039

[jasimp]

2053

[BearofNH]

2063

2^11 + 2^2^2 - 1

The usual convention is that a^b^c associates right-to-left, i.e. is a^(b^c).

[jasimp]

2069

[BearofNH]

2081

Kicking off a "prime decade", sort of the opposite of a "prime desert".

[scudzilla]

2083

[jasimp]

2087

[BearofNH]

2089

End of a prime decade

[jasimp]

2099

[BearofNH]

2111

Start with 2111. Square it: 4456321. Reverse digits: 1236544. Extract square root: 1112. Voila, the reverse of 2111 (!)

(This always works as long as there are no carries in the additions done during squaring. Still, there aren't many 4-digit primes that qualify this way.)

[jasimp]

2113

[BearofNH]

2129

2^11 + 3^4

[jasimp]

2131

[BearofNH]

2137

7 is prime, 37 is prime, 137 is prime and so is 2137. (And the chain goes on...)

[jasimp]

2141

[BearofNH]

2143

sqrt(sqrt(2143/22)) = pi to 8 decimal places

[scudzilla]

2153

[jasimp]

2161

[BearofNH]

2179

You can rearrange the digits to form the Hardy-Ramanujan constant 1729.