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:
“My prime of youth is but a frost of cares,
My feast of joy is but a dish of pain,
My crop of corn is but a field of tares,
And all my good is but vain hope of gain:
The day is past, and yet I saw no sun,
And now I live, and now my life is done.”
—Chidiock Tichborne (1558–1586)
“Its quick silver bell beating, beating
And down the dark one ruby flare
Pulsing out red light like an artery,”
—Karl Shapiro (b. 1913)
“One murder makes a villain, millions a hero. Numbers sanctify, my good fellow.”
—Charlie Chaplin (1889–1977)