|
| |
|
|
A114410
|
|
Cumulative sum of double primorials (A079078).
|
|
1
| |
|
|
1, 3, 6, 16, 37, 147, 420, 2290, 7477, 50487, 200910, 1534220, 7099871, 61765581, 301088574, 2870376944, 15554495573, 167142509403, 940873745772, 9581390534082, 64516308316281, 695274033862911, 5035132538656632
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| The cumulative sum is prime for a(2) = 3, a(4) = 37, a(8) = 7477, a(12) = 7099871, a(16) = 15554495573. The sum a(n) is semiprime for n = 2, 9.
|
|
|
FORMULA
| a(n) = 0## + 1## + ... + n##, where n## = p(n)*(n-2)##, where p(n) is the n-th prime.
|
|
|
EXAMPLE
| n 0## + ... + n##
0 1.
1 1+2 = 3.
2 1+2+3 = 6.
3 1+2+3+10 = 16.
4 1+2+3+10+21 = 37.
5 1+2+3+10+21+110 = 147.
6 1+2+3+10+21+110+273 = 420.
7 1+2+3+10+21+110+273+1870 = 2290.
8 1+2+3+10+21+110+273+1870+5187 = 7477.
9 1+2+3+10+21+110+273+1870+5187+ 43010 = 50487.
10 1+2+3+10+21+110+273+1870+5187+ 43010 + 150423 = 200910.
|
|
|
CROSSREFS
| Cf. A079078.
Sequence in context: A089406 A027852 A203068 * A190735 A096588 A073079
Adjacent sequences: A114407 A114408 A114409 * A114411 A114412 A114413
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Jonathan Vos Post (jvospost3(AT)gmail.com), Feb 12 2006
|
| |
|
|
