|
Search: id:A034094
|
|
|
| A034094 |
|
(-1)sigma perfect numbers: (-1)sigma(a) = m*a for some integer m, where if a = Product p(i)^r(i) then (-1)sigma(a) = Product (-1+Sum p(i)^s(i), s(i)=1 to r(i)). |
|
+0
4
|
|
| 20, 312, 9744, 29280, 53352, 1666224, 5006880, 106798080, 980733600, 133301760, 9099742080, 22794600960, 1556055895680, 3577201689600, 4464942451200, 380428773854896765462278360268800000
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
The indices of some terms are 1, so these numbers are fixed points of (-1)sigma.
|
|
EXAMPLE
|
Factorizations 2^2*5, 2^3*3*13, 2^4*3*7*29, 2^5*3*5*61, 2^3*3^3*13*19, 2^4*3^3*7*19*29, 2^5*3^3*5*19*61, 2^10*3*5*17*409, 2^5*3^2*5^2*7*11*29*61, 2^9*3*5*17*1021, 2^7*3*5*11^2*13*23*131, 2^9*3^3*5*17*19*1021, 2^7*3^3*5*11^2*13*19*23*131, 2^10*3^2*5^2*7*11*17*29*409, 2^9*3^2*5^2*7*11*17*29*1021, 2^24*3^3*5^5*7^2*11*17*19*29*61*233*239*467*479*70051
|
|
CROSSREFS
|
Cf. A034095, A049060.
Sequence in context: A016190 A016188 A006300 this_sequence A011197 A054621 A111778
Adjacent sequences: A034091 A034092 A034093 this_sequence A034095 A034096 A034097
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp)
|
|
|
Search completed in 0.002 seconds
|
