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A127066
a(0)=1; for n > 0, a(n) = a(n-1) + a(prime(n)(mod n)), where prime(n) is the n-th prime.
1
1, 2, 4, 8, 16, 18, 20, 28, 36, 54, 108, 162, 164, 168, 170, 174, 192, 228, 256, 364, 526, 634, 802, 972, 1200, 2002, 2974, 3776, 4748, 5550, 6522, 6530, 6538, 6556, 6564, 6618, 6646, 6700, 6862, 7024, 7192, 7366, 7534, 7898, 8126, 8354, 8528, 9500, 16030
OFFSET
0,2
EXAMPLE
The 7th prime, 17, is congruent to 3 (mod 7). So a(7) = a(6) + a(3) = 20 + 8 = 28.
MAPLE
a:=proc(n) if n=0 then 1 else a(n-1)+a(ithprime(n) mod n) fi end: seq(a(n), n=0..55); # Emeric Deutsch, Mar 23 2007
MATHEMATICA
f[l_List] := Block[{n = Length[l]}, Append[l, l[[Mod[Prime[n], n] + 1]] + l[[ -1]]]]; Nest[f, {1}, 50] (* Ray Chandler, Mar 23 2007 *)
CROSSREFS
Sequence in context: A018510 A018366 A216781 * A331382 A154362 A226221
KEYWORD
nonn
AUTHOR
Leroy Quet, Mar 21 2007
EXTENSIONS
More terms from Emeric Deutsch and Ray Chandler, Mar 23 2007
STATUS
approved