OFFSET
0,3
EXAMPLE
a(0)=0 because 5^0+2^0=1+1=2 is prime,
a(5)=7 because 5^5+2^7=3125+128=3253 is prime,
MATHEMATICA
lm[n_]:=Module[{c=5^n, m=1}, While[CompositeQ[c+2^m], m++]; m]; Join[ {0}, Array[lm, 80]] (* Harvey P. Dale, Jul 18 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 12 2006
STATUS
approved