A140235 Partial sum of non-semiprimes A100959.

1, 3, 6, 11, 18, 26, 37, 49, 62, 78, 95, 113, 132, 152, 175, 199, 226, 254, 283, 313, 344, 376, 412, 449, 489, 530, 572, 615, 659, 704, 751, 799, 849, 901, 954, 1008, 1064, 1123, 1183, 1244, 1307, 1371, 1437, 1504, 1572, 1642, 1713, 1785, 1858, 1933, 2009

Offset

1,2

Comments

This is to semiprimes A001358 as A051352 is to primes A000040. Equivalently, this is to non-semiprimes A100959 as A051349 is to nonprimes A018252.

Links

Table of n, a(n) for n=1..51.

Formula

a(n) = Sum{k=1..n} A100959(k).

Example

a(5) = 18 = 1 + 2 + 3 + 5 + 7.

Mathematica

Accumulate[Select[Range[100], PrimeOmega[#]!=2&]] (* Harvey P. Dale, Aug 22 2021 *)

Crossrefs

Cf. A000217, A001358, A018252, A034387, A051349, A051352, A062198, A072000, A100959, A140234.

Sequence in context: A025210 A340648 A140126 * A224214 A010000 A183199

Adjacent sequences: A140232 A140233 A140234 * A140236 A140237 A140238

Keyword

easy,nonn

Author

Jonathan Vos Post, May 13 2008

Extensions

Corrected and edited by Giovanni Resta, Jun 20 2016

Status

approved