OFFSET
1,1
COMMENTS
Suggested in a discussion in Mersenneforum, with contributions by users (among others) "davar55", Benjamin R. Buhrow, and Charles R Greathouse IV. The latter calculated the terms a(1)-a(9) of this sequence (see link).
LINKS
Charles R Greathouse IV and others, Sums of Squares, thread in Mersenneforum, December 2010.
EXAMPLE
a(1) = 11: 2^2 = 4, 2^2 + 3^3 = 31, 2^2 + 3^3 + 5^5 = 3156, 2^2 + 3^3 + 5^5 + 7^7 = 826699, 2^2 + 3^3 + 5^5 + 7^7 + 11^11 = 285312497310 -> smallest sum divisible by 10^1.
PROG
(PARI) for(n=1, 4, my(n10=10^n, s=0); forprime(p=2, oo, s+=p^p; if(!(s%n10), print1(p, ", "); break)))
CROSSREFS
KEYWORD
nonn,more,hard
AUTHOR
Hugo Pfoertner, Dec 10 2019
EXTENSIONS
a(10)-a(11) from Giovanni Resta, Dec 11 2019
STATUS
approved