A168350 Sum of first n non-single or nonisolated numbers.

0, 1, 4, 9, 16, 24, 33, 43, 54, 67, 81, 96, 112, 129, 148, 168, 189, 211, 235, 260, 286, 313, 341, 370, 401, 433, 466, 500, 535, 571, 609, 648, 688, 729, 772, 816, 861, 907, 955, 1004, 1054, 1105, 1157, 1211, 1266, 1322, 1379, 1437, 1496, 1557, 1619, 1682

Offset

1,3

Links

Table of n, a(n) for n=1..52.

Formula

a(n)=sum{j=1..n} A167707(j).

Example

a(1)=0, a(2)=0+1=1, a(3)=0+1+3=4.

Crossrefs

Cf. A167707.

Sequence in context: A320891 A161697 A078593 * A281151 A337722 A052117

Adjacent sequences: A168347 A168348 A168349 * A168351 A168352 A168353

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 23 2009

Extensions

Formula and A-number corrected and entries checked by R. J. Mathar, Nov 24 2009

Status

approved