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A054750
Smallest prime number whose digits sum to n-th prime.
9
2, 3, 5, 7, 29, 67, 89, 199, 599, 2999, 4999, 29989, 59999, 79999, 389999, 989999, 6999899, 8989999, 59899999, 89999999, 289999999, 799999999, 3999998999, 19999997999, 79999999999, 399999998999, 599999899999, 999998999999
OFFSET
1,1
COMMENTS
a(n) >= A051885(A000040(n)). Indices n for which the equality holds are listed in A055019.
a(n) >= A046864(n). - Michel Marcus, Nov 01 2015
LINKS
Chris Caldwell and G. L. Honaker, Jr., Prime curio for 8999
EXAMPLE
E.g. a(7)=89 because 8+9=17 and 17 is the 7th prime.
PROG
(PARI) a(n) = {my(k=2); my(p=prime(n)); while((sumdigits(k) != prime(n)), k=nextprime(k+1)); k; } \\ Michel Marcus, Nov 01 2015
KEYWORD
base,nonn
AUTHOR
G. L. Honaker, Jr., Apr 24 2000
EXTENSIONS
More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), May 31 2000
Edited and extended by Robert G. Wilson v, Feb 26 2002
STATUS
approved