13640692231domain: NAppears in sequencesPrimes of the form 1 - sigma(n) + sigma(n)^2 - sigma(n)^3 + sigma(n)^4.at n=22A259412Primes of the form 1 - sigma(n) + sigma(n)^2 - sigma(n)^3 + sigma(n)^4.at n=24A259412