A173616 - OEIS

%I #12 Mar 31 2012 20:30:53

%S 1,11,117,1178,11787,117870,1178701,11787019,117870197,1178701972,

%T 11787019723,117870197230,1178701972308,11787019723085,

%U 117870197230855,1178701972308551,11787019723085519,117870197230855196,1178701972308551965,11787019723085519654

%N The first n digits of Reverse(A002275(n)^A002275(n))

%C 0 <= a(n)-10*a(n-1)<10

%C All terms are prefixes of later terms.

%e reverse(11^11)=116076113582 =>a(2)=11 reverse(111^111)=117...... =>a(3)=117 reverse(1111^111)=1178....=>a(4)=1178

%t repunit[n_] := Sum[10^i, {i, 0, n - 1}]; a[n_]:= FromDigits[Reverse[IntegerDigits[repunit[n]^repunit[n]]][[1 ;; n]]]; Table[a[n], {n, 1, 7}]

%t repunit[n_] := Sum[10^i, {i, 0, n - 1}];h[n_] := If[(b = (1 +Floor@Log[10,aux = FromDigits@Reverse@IntegerDigits@PowerMod[repunit[n], repunit[n], 10^n]])) < n, aux*10^(n - b), aux] (*Suggested by Jorge Jimenez Meana*) [From _José María Grau Ribas_, Mar 01 2010]

%K base,easy,nonn

%O 1,2

%A _José María Grau Ribas_, Feb 22 2010