Cool, I hadn't run into it before so thanks for introducing me!
I was going to include the digits for comparison, but yes, on second thought 6002 digits is probably too much for polite inclusion in a HN post.
I was going to include the digits for comparison, but yes, on second thought 6002 digits is probably too much for polite inclusion in a HN post.
OEIS says "19937 ones in a row" isn't prime, but "1031 ones in a row" is.
And "8177207 ones in a row" is at least a probable prime. (Which you can maybe remember as a seven-digit phone number, or as either BITTZOT or LOZLLIB depending on how you prefer to hold your calculator. But those mnemonics are wasted if (10^{81777207}-1)/9 turns out to be merely pseudoprime.)