14917...53217 (42-digits)

This number is a prime.

                              14 9172716659 7036592132 9742264032 9712953217

The start of a sequence of 22 type 4k+1 primes such that every next term is equal to a*b+1, where a and b are the square decomposition of the previous prime, i.e., p_(i-1) = a^2+b^2, p_i = a*b+1: 149172716659703659213297422640329712953217 -> 12099688650324688968668103045607614193 -> 11487118307550560664784913589052510969 -> 42876888150434052973459919973016921 -> 33705905571268669976792858692557481 -> 7031965605758664339776091952244521 -> 248295920404475618157548087881 -> 1623255678955050222529829281 -> 3853435225785707882041 -> 10815509128000081 -> 324264641521 -> 314582278321 -> 25902808801 -> 806229241 -> 549556801 -> 16454881 -> 15569401 -> 12743641 -> 6978841 -> 2317561 -> 1921921 -> 903841 -> 196561 -> 129481 -> 0. [Rivera]