A099072 First differences of A000960, divided by 2.

1, 2, 3, 3, 4, 6, 5, 7, 8, 6, 9, 12, 7, 17, 13, 8, 15, 18, 9, 21, 19, 6, 30, 11, 24, 19, 23, 18, 30, 27, 22, 18, 42, 11, 30, 42, 9, 39, 36, 30, 19, 56, 6, 48, 57, 13, 44, 46, 17, 45, 69, 13, 41, 49, 56, 27, 85, 18, 30, 84, 26, 64, 26, 64, 47, 54, 45, 94, 17, 36, 85, 60, 23, 79, 98

Offset

1,2

Links

Table of n, a(n) for n=1..75.

Mathematica

del[lst_, k_] := lst[[ Select[ Range[ Length[ lst]], Mod[ #, k] != 0 &]]]; For[ k = 2; s = Range[10000], k <= Length[s], k++, s = del[s, k]]; (Drop[s, 1] - Drop[s, -1])/2

Crossrefs

Cf. A000960, A056526.

Sequence in context: A281365 A304705 A131187 * A257241 A239964 A290585

Adjacent sequences: A099069 A099070 A099071 * A099073 A099074 A099075

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 15 2004

Extensions

More terms from Robert G. Wilson v, Nov 15 2004

Status

approved