OFFSET
1,4
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = n - 2*ceiling(n/8) + 2 if n == 1 (mod 8) a(n) = n - 2*ceiling(n/8) otherwise.
EXAMPLE
Because 53-1 = 52 is not congruent to 1 (mod 8); a(71) = 71 - 2*ceiling(71/8) = 71 - 2*9 = 53.
MATHEMATICA
Table[Sum[KroneckerSymbol[j+1, j], {j, n}], {n, 80}] (* G. C. Greubel, Mar 17 2019 *)
PROG
(PARI) for(n=1, 100, print1(sum(i=1, n, kronecker(i+1, i)), ", "))
(Sage) [sum(kronecker_symbol(j+1, j) for j in (1..n)) for n in (1..80)] # G. C. Greubel, Mar 17 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Jun 14 2002
STATUS
approved