A105300 Primes formed by reverse concatenation of 8 consecutive triangular numbers.

1178111628114761132511175110261087810731, 779376778128776881775635774390773146771903770661, 852165850860849556848253846951845650844350843051

Offset

1,1

Links

Table of n, a(n) for n=1..3.

Example

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.

Mathematica

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

Crossrefs

Sequence in context: A329659 A336775 A095472 * A292992 A375648 A008870

Adjacent sequences: A105297 A105298 A105299 * A105301 A105302 A105303

Keyword

base,nonn,bref

Author

Shyam Sunder Gupta, Apr 25 2005

Status

approved