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%I #14 Jan 01 2024 11:43:24
%S 0,1,3,7,13,19,21,23,27,33,39,41,43,47,53,59,61,63,67,73,79,81,83,87,
%T 93,99,101,103,107,113,119,121,123,127,133,139,141,143,147,153,159,
%U 161,163,167,173,179,181,183,187,193,199,201,203,207,213,219,221,223,227,233
%N a(n) = a(n-1)+ (abs(2^a(n-1)*a(n-1)) mod 10).
%C Apart from the first two terms all the other numbers can be formed adding in sequence 2, 4, 6, 6, 2 and so on. Example 1+(2)=3; 3+(4)=7; 7+(6)=13; 13+(6)=19; 19+(2)=21; ...
%H Harvey P. Dale, <a href="/A118667/b118667.txt">Table of n, a(n) for n = 0..250</a>
%F a(n) = a(n-1)+ (abs(2^a(n-1)*a(n-1)) mod 10) being a(0) = 0 and a(1) = 1
%e a(2)= 1 + abs(2^1 *1)mod 10 = 1 + 2 mod 10 = 1 + 2 = 3
%p ANM:=proc(N) local an,i,anminus1,anplus1; anminus1:=0; an:=1; print (anminus1); print (an); for i from 2 by 1 to N do anplus1:=an+(abs(2^an*an) mod 10); print(anplus1); anminus1:=an; an:=anplus1; od; end: ANM(100);
%t Join[{0},NestList[#+Mod[Abs[2^# #],10]&,1,60]] (* _Harvey P. Dale_, Jul 01 2022 *)
%K nonn
%O 0,3
%A _Paolo P. Lava_ and _Giorgio Balzarotti_, May 19 2006
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