OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
a(1)=136101521 because 136101521 is the prime formed by concatenation of 6 consecutive triangular numbers i.e. 1,3,6,10,15 and 21.
MATHEMATICA
Select[FromDigits[Flatten[IntegerDigits/@#]]&/@Partition[Accumulate[ Range[ 500]], 6, 1], PrimeQ] (* Harvey P. Dale, Aug 27 2019 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Shyam Sunder Gupta, Apr 25 2005
STATUS
approved