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%I #24 Aug 19 2021 11:24:32
%S 14,16,34,36,54,56,74,76,94,96,114,116,134,136,154,156,174,176,194,
%T 196,214,216,234,236,254,256,274,276,294,296,314,316,334,336,354,356,
%U 374,376,394,396,414,416,434,436,454,456,474,476,494,496,514,516,534,536
%N Numbers k such that k and 2^k end with the same digit.
%C Also numbers k such that k and (2^(2*h+1))^k (for n>=0) end with the same digit. - _Bruno Berselli_, Dec 13 2018
%H <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,-1).
%F From _Colin Barker_, Dec 01 2012: (Start)
%F G.f.: 2*x*(2*x^2 + x + 7)/((x - 1)^2*(x + 1)).
%F a(n) = a(n-1) + a(n-2) - a(n-3).
%F a(n) = 10*n - 4*(-1)^n. (End)
%e 2^36 = 68719476736 hence 36 is in the sequence.
%t LinearRecurrence[{1,1,-1},{14,16,34},70] (* _Harvey P. Dale_, Aug 19 2021 *)
%o (PARI) isok(n) = (2^n - n) % 10 == 0; \\ _Michel Marcus_, Nov 23 2013
%Y Cf. A064541.
%K nonn,base,easy
%O 1,1
%A _Benoit Cloitre_, Mar 07 2002
%E Example corrected by _Michel Marcus_, Nov 23 2013
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