OFFSET
1,1
COMMENTS
Sum of digits of a(n) = prime(n).
FORMULA
EXAMPLE
prime(7)=17; (17-1)/2=8; a(7) = 222222221, 8*"2" concatenated with "1".
PROG
(PARI) a(n) = if (n==1, 2, fromdigits(concat(vector((prime(n)-1)/2, k, 2), 1))); \\ Michel Marcus, Mar 15 2022
CROSSREFS
KEYWORD
easy,nonn,base
AUTHOR
Ctibor O. Zizka, Apr 05 2008
EXTENSIONS
More terms from Michel Marcus, Mar 15 2022
STATUS
approved