## Remarks ## https://en.wikipedia.org/wiki/Perrin_number import math def IsPrime(nInput): for nDiv in range(2, int(math.sqrt(nInput)) + 1): if nInput % nDiv == 0: return False return True arrPerrinPrime = [] arrPerrinNum = [] arrPerrinNum.append(3) arrPerrinNum.append(0) arrPerrinNum.append(2) arrPerrinPrime.append(2) arrPerrinPrime.append(3) while len(arrPerrinPrime) < 13: nNuNum = arrPerrinNum[-2] + arrPerrinNum[-3] arrPerrinNum.append(nNuNum) if not IsPrime(nNuNum): continue nCount = arrPerrinPrime.count(nNuNum) if nCount > 0: continue arrPerrinPrime.append(nNuNum) print (arrPerrinPrime)