A167885 n-th single or isolated number*n-th non-single or nonisolated number.

0, 4, 18, 60, 126, 184, 270, 370, 462, 611, 742, 900, 1072, 1224, 1501, 1660, 1869, 2134, 2448, 2700, 2938, 3429, 3668, 4002, 4650, 5024, 5379, 5678, 6055, 6480, 7296, 7722, 8440, 9143, 9804, 10252, 10800, 11546, 12336, 12887, 13500, 14127, 14664

Offset

1,2

Links

Table of n, a(n) for n=1..43.

Formula

a(n)=A167706(n)*A167707(n).

Example

a(1)=2*0=0, a(2)=4*1=4, a(3)=6*3=18, a(4)=12*5=60.

Crossrefs

Cf. A167706, A167707.

Sequence in context: A027286 A119044 A058851 * A212521 A278406 A192069

Adjacent sequences: A167882 A167883 A167884 * A167886 A167887 A167888

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 14 2009, Nov 15 2009

Extensions

All terms > 1900 corrected by R. J. Mathar, May 30 2010

Status

approved