|
| |
|
|
A106550
|
|
a(n) = n-th semiprime + (concatenation of its two factors, smallest factor first).
|
|
4
| |
|
|
26, 29, 42, 35, 41, 50, 58, 233, 80, 239, 344, 251, 92, 257, 352, 269, 126, 368, 566, 376, 2, 87, 293, 578, 392, 311, 788, 323, 602, 329, 416, 804, 424, 341, 614, 359, 448, 638, 377, 836, 1232, 383, 464, 472, 852, 401, 488, 413, 1256, 674, 419, 686, 437, 512, 884
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
FORMULA
| a(n) = A001358(n) + A106554(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 19 2005
|
|
|
EXAMPLE
| First semiprime is 4; 4 is 2*2; 26=4+22.
Second semiprime is 6; 6 is 2*3; 29=6+23.
Third semiprime is 9; 9 is 3*3; 41=9+33.
Fourth semiprime is 10; 10 is 2*5; 35=10+25.
|
|
|
CROSSREFS
| Cf. A084126, A084127, A001358.
Sequence in context: A081644 A055109 A106552 * A069962 A178098 A045163
Adjacent sequences: A106547 A106548 A106549 * A106551 A106552 A106553
|
|
|
KEYWORD
| base,easy,nonn
|
|
|
AUTHOR
| Eric Angelini (eric.angelini(AT)kntv.be), May 09 2005
|
|
|
EXTENSIONS
| More terms from Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 19 2005
|
| |
|
|
