A105299 Primes formed by concatenation of 8 consecutive triangular numbers.

105120136153171190210231, 351378406435465496528561, 8425584666850788549185905863208673687153, 649230650370651511652653653796654940656085657231

Offset

1,1

Links

Table of n, a(n) for n=1..4.

Example

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.

Mathematica

Select[FromDigits[Flatten[IntegerDigits/@#]]& /@Partition[Accumulate[Range[2000]], 8, 1], PrimeQ] (* Harvey P. Dale, Mar 20 2011 *)

Crossrefs

Sequence in context: A216854 A008916 A292859 * A340397 A094232 A234594

Adjacent sequences: A105296 A105297 A105298 * A105300 A105301 A105302

Keyword

base,nonn

Author

Shyam Sunder Gupta, Apr 25 2005

Status

approved