The Ramsey Number R(5,5)

There are fans, among math buffs, of e and of π.
The ratio golden has legions who sigh,
In reverent awe at its beauty ideal.
Euler's γ has got its own quirky appeal.
But what makes me feel tingly, aroused, and alive
Is the mystical integer R(5,5). [Read "R of five five"]

Like Batman and Robin, its everyday face
Is a secret identity quite commonplace.
It's an integer, experts on graph theory state,
At least 43 and at most 48.
And combinatorists laboriously strive
To narrow the bounds known for R(5,5).

It's a quite element'ry idea to define
(Though I don't want to try that in meter and rhyme).
A short, simple program in Python or C
Has no trouble at all finding R(3,3)
But the stars in the sky will no longer survive
Ere it prints out the value of R(5,5).

Said Erdos: "If aliens from far outer space
Want to know, or they'll wipe out the whole human race
If we join all our forces, perhaps we'll contrive
To tell them the value of R(5,5).
But we'll certainly be in a hell of a fix
If they ask for the value of R(6,6)."

Note

This is part of the collection Verses for the Information Age by Ernest Davis