OFFSET
1,2
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, Colored logarithmic scatterplot of the first 2500 terms (where the color is function of the last prime number encountered) [A remarkable graph. - N. J. A. Sloane, Feb 13 2021]
MATHEMATICA
Block[{a = {1, 2}}, Do[AppendTo[a, Which[MemberQ[{##}, 1], Abs[#1 + #2], SameQ @@ PrimeQ[{##}], Abs[#1 - #2], True, Abs[#1 + #2]]] & @@ a[[-2 ;; -1]], {i, 49}]; a] (* Michael De Vlieger, Feb 05 2021 *)
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Brian Beard, Feb 05 2021
STATUS
approved