A105300 - OEIS

%I #6 Mar 01 2023 17:11:27

%S 1178111628114761132511175110261087810731,

%T 779376778128776881775635774390773146771903770661,

%U 852165850860849556848253846951845650844350843051

%N Primes formed by reverse concatenation of 8 consecutive triangular numbers.

%e a(1)=1178111628114761132511175110261087810731 because 1178111628114761132511175110261087810731 is the prime formed by reverse concatenation of 8 consecutive triangular numbers i.e. 10731,10878,11026,11175,11325,11476,11628 and 11781.

%t Select[FromDigits[Flatten[(IntegerDigits/@Reverse[#])]]&/@Partition[ Accumulate[ Range[ 2000]],8,1],PrimeQ] (* _Harvey P. Dale_, Mar 01 2023 *)

%K base,nonn,bref

%O 1,1

%A _Shyam Sunder Gupta_, Apr 25 2005