OFFSET
1,2
LINKS
Peter Kagey, Table of n, a(n) for n = 1..10000
MATHEMATICA
c = Select[Range@ 600, CompositeQ]; a = {1, 4}; Do[k = 6; While[Or[PrimeQ@ k, MemberQ[a, k], CoprimeQ[a[[i - 1]], k]], k++]; AppendTo[a, k], {i, 3, Length@c + 1}]; Flatten@ Position[Union /@ Transpose@ {Rest@ a, c}, w_ /; Length@ w == 1] (* Michael De Vlieger, Sep 01 2016 *)
PROG
(Haskell)
a276375 n = a276375_list !! (n - 1)
a276375_list = filter (\i -> a240024 (i + 1) == a002808 i) [1..]
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Kagey, Aug 31 2016
STATUS
approved