Prime Bell Numbers
The first few Bell numbers that are primes are:
- 2, 5, 877, 27644437, 35742549198872617291353508656626642567, 359334085968622831041960188598043661065388726959079837 (sequence A051131 in OEIS)
corresponding to the indices 2, 3, 7, 13, 42 and 55 (sequence A051130 in OEIS).
The next prime is B2841, which is approximately 9.30740105 × 106538. As of 2006, it is the largest known prime Bell number. Phil Carmody showed it was a probable prime in 2002. After 17 months of computation with Marcel Martin's ECPP program Primo, Ignacio Larrosa Cañestro proved it to be prime in 2004. He ruled out any other possible primes below B6000, later extended to B30447 by Eric Weisstein.
Read more about this topic: Bell Number
Famous quotes containing the words prime, bell and/or numbers:
“Faith in reason as a prime motor is no longer the criterion of the sound mind, any more than faith in the Bible is the criterion of righteous intention.”
—George Bernard Shaw (1856–1950)
“You owe me ten shillings,
Say the bells of St. Helen’s.
When will you pay me?
Say the bells of Old Bailey.
When I grow rich,
Say the bells of Shoreditch.
Pray when will that be?
Say the bells of Stepney.
I am sure I don’t know,
Says the great bell of Bow.”
—Unknown. The Bells of London (l. 13–22)
“Out of the darkness where Philomela sat,
Her fairy numbers issued. What then ailed me?
My ears are called capacious but they failed me,
Her classics registered a little flat!
I rose, and venomously spat.”
—John Crowe Ransom (1888–1974)