|
| |
|
|
A162708
|
|
Numbers that are the sum of two reversed primes in more than one way.
|
|
0
| |
|
|
10, 14, 16, 18, 19, 20, 21, 22, 24, 27, 28, 30, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 54, 66, 68, 69, 70, 72, 73, 74, 75, 76, 78, 79, 81, 82, 84, 85, 86, 87, 88, 89, 90, 92, 93, 94, 95, 96, 97, 98, 99, 100, 102, 103, 104, 105, 106, 107, 108, 109
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,1
|
|
|
COMMENTS
| Subsequence of A162706. - R. J. Mathar, Jul 13 2009
|
|
|
EXAMPLE
| 14 = R(7)+R(7)=R(3)+R(11).
28 = R(11)+R(71)=11+17 = R(41)+R(41)=14+14.
33 = 2+31 = R(2)+R(13) = 16+17 = R(61)+R(71).
36 = R(2) +R(43)=2+34 = R(5)+R(13)=5+31.
|
|
|
MAPLE
| read("transforms") ; A055642 := proc(n) max(1, ilog10(n)+1) ; end:
A004087 := proc(n) option remember; digrev(ithprime(n)) ; end:
isA162708 := proc(n) c := 0 ; for i from 1 do p := ithprime(i) ; if A055642(p) > A055642(n) then break; fi; for j from 1 to i do if A004087(i)+A004087(j) = n then c := c+1; fi; od: od: RETURN(c > 1); end:
for n from 1 to 200 do if isA162708(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Jul 13 2009
|
|
|
CROSSREFS
| Sequence in context: A171156 A088711 A154774 * A067188 A092632 A055197
Adjacent sequences: A162705 A162706 A162707 * A162709 A162710 A162711
|
|
|
KEYWORD
| nonn,base
|
|
|
AUTHOR
| Claudio L Meller (claudiomeller(AT)gmail.com), Jul 11 2009
|
|
|
EXTENSIONS
| Missing terms 14, 33, etc. inserted by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 13 2009
|
| |
|
|
