OFFSET
0,1
COMMENTS
From Robert G. Wilson v, Aug 11 2010: (Start)
A179975 n's such that a(n)=1: 3, 335, ..., .
A179975 First occurrence of k: 3, 18, 2, ???, 1, 4, 50, 162, 9, 335, 17, 19, 68, 7, 27, ..., .
Records: 5, 6, 14, 19, 21, 42, 93, 111, 337, 449, 862, 1049, 1062, 1122, 1280, 2278, 3168, 4290, ..., . (End)
LINKS
Robert G. Wilson v, Table of n, a(n) for n = 0..400.
Dario Alejandro Alpern, Brilliant numbers
EXAMPLE
a(0)=5 because 5=2+3
a(1)=3 because 30=13+17
a(2)=1 because 100=47+53
a(3)=6 because 6000=2999+3001.
MATHEMATICA
Join[{5, 3}, Reap[Do[Do[n=10^m k; If[n==PreviousPrime[n/2]+NextPrime[n/2], Sow[k]; Break[]], {k, 2000}], {m, 2, 50}]][[2, 1]]]
f[n_] := Block[{k = 1, tn = 10^n}, While[h = k*tn/2; NextPrime[h, -1] + NextPrime@h != k*tn, k++ ]; k]; f[1] = 3; Array[f, 70, 0] (* Robert G. Wilson v, Aug 11 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Aug 04 2010
EXTENSIONS
More terms from Robert G. Wilson v, Aug 11 2010
STATUS
approved