login
A173287
Intersection of A173286 and A173269.
0
1, 2, 8, 15, 63, 152, 2306, 2373
OFFSET
1,2
EXAMPLE
a(1)=1 because 2*p(p(p(1)))-3=7=prime, 2*p(p(1))-3=3=prime and 3*p(p(p(1)))-2=13=prime, 3*p(p(1))-2=7=prime; a(2)=2 because 2*p(p(p(2)))-3=19=prime, 3p(p(2))-2=13=prime and 3*p(p(p(2)))-2=31=prime, 3*p(p(2))-2=13=prime; a(3)=8 because 2*p(p(p(8)))-3=991=prime, 2*p(p(8))-3=199=prime and 3*p(p(p(8)))-2=659=prime, 3*p(p(8))-2=131=prime; a(4)=15 because 2*p(p(p(15)))-3=3889=prime, 3*p(p(15))-2=631=prime and 3*p(p(p(15)))-2=2591=prime, 2*p(p(15))-3=439=prime.
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Definition corrected and 4 terms appended by R. J. Mathar, Mar 01 2010
STATUS
approved