login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A069620
a(1) = 8; a(2n) = smallest prime that is a right concatenation of a(2n-1) and a number with no insignificant zeros and a(2n+1) = smallest prime ending in ( the least significant digits) a(2n-1). Alternate left and right concatenation yielding primes.
1
8, 83, 283, 2833, 32833, 328331, 2328331, 232833127, 3232833127, 323283312749, 14323283312749, 1432328331274927, 281432328331274927, 28143232833127492741, 3628143232833127492741, 36281432328331274927411
OFFSET
1,1
EXAMPLE
a(4) = 2833 staring with a(3) =283 and a(5) = 32833 ending in a(4) = 2833.
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Mar 27 2002
EXTENSIONS
More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Mar 30 2003
STATUS
approved