|
| |
|
|
A237521
|
|
Numbers n such that phi(n) + sigma(n) = reversal(n) + 2.
|
|
4
|
| |
|
|
|
OFFSET
|
1,1
|
|
|
COMMENTS
|
a(5), if it exists, is larger than 10^13.
Up to 10^13 the equation phi(n) + sigma(n) = reversal(n) - 2 is satisfied only by n = 26330276.
|
|
|
LINKS
|
Table of n, a(n) for n=1..4.
|
|
|
EXAMPLE
|
22605 is in the sequence because phi(22605) = 10880, sigma(22605) = 39744, and 10880 + 39744 = 50622 + 2, where 50622 is the reversal of 22605.
|
|
|
CROSSREFS
|
Cf. A070272, A230004, A230005, A230006, A230019, A136544, A237522.
Sequence in context: A290741 A261362 A132942 * A131558 A133857 A232869
Adjacent sequences: A237518 A237519 A237520 * A237522 A237523 A237524
|
|
|
KEYWORD
|
nonn,base,more
|
|
|
AUTHOR
|
Giovanni Resta, Feb 08 2014
|
|
|
STATUS
|
approved
|
| |
|
|
