OFFSET
1,1
COMMENTS
Let p be a Wagstaff prime related to The New Mersenne Conjecture. Then (3p-2)(3p-1)/2 gives the perfect number whose index it is.
LINKS
Caldwell and Honaker, 56713...35243 (38-digits), Prime Curios!
Eric Weisstein's World of Mathematics, New Mersenne Prime Conjecture
EXAMPLE
For p = 3, (3*3-2)*(3*3-1)/2 = 28 and for p = 11, (3*11-2)(3*11-1)/2 = 496.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Steve Homewood, Apr 05 2018
STATUS
approved