1,1

a(1)=105120136153171190210231 because 105120136153171190210231 is the prime formed by concatenation of 8 consecutive triangular numbers i.e. 105,120,136,153,171,190,210 and 231.

Adjacent sequences: A105296 A105297 A105298 this_sequence A105300 A105301 A105302

Sequence in context: A095440 A082566 A008916 this_sequence A094232 A132185 A003942

base,nonn

Shyam Sunder Gupta (guptass(AT)rediffmail.com), Apr 25 2005