1,2

Table of n, a(n) for n=1..72.

a(2) = 2 is prime a(2) +a(3) +a(5) = 2 +3 +6 = 11.

a(4) = 4 is composite, a(4) +a(6) +a(8) + a(9) = 4 +5 + 7+ 9 = 25 is composite.

Cf. A083180, A083181.

Cf. A073885.

Sequence in context: A129258 A256988 A104650 * A123503 A123717 A123718

Adjacent sequences: A083176 A083177 A083178 * A083180 A083181 A083182

nonn

Amarnath Murthy, Apr 26 2003

More terms from David Wasserman, Oct 26 2004

approved