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 A095412 Exponents k such that the sum of decimal digits of 2^k is also a power of 2. 6
 0, 1, 2, 3, 9, 36, 85, 176, 194, 200, 375, 1517, 1523, 3042, 5953, 6043, 6109, 12068, 12104, 96251, 193734, 386797, 387589, 1545477, 3092224, 3098800, 6188717, 6191693, 6199469, 24753865, 99084345 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Table of n, a(n) for n=1..31. EXAMPLE 2^9 = 512 with digit sum = 8; 2^36 = 68719476736 with digit sum = 64; 2^85 = 38685626227668133590597632 with digit sum = 128; 2^96251 has a decimal digit sum of 131072. MATHEMATICA Do[If[IntegerQ[Log[2, Plus@@IntegerDigits[2^n]]], Print[n] ], {n, 0, 10^6}]; PROG (PARI) isp(n) = (n==1) || (n==2) || (ispower(n, , &k) && (k==2)); isok(n) = isp(sumdigits(2^n)); \\ Michel Marcus, Apr 25 2017 CROSSREFS Cf. A001370 (sum of digits of 2^n). Sequence in context: A064020 A204442 A306523 * A074428 A328436 A125052 Adjacent sequences: A095409 A095410 A095411 * A095413 A095414 A095415 KEYWORD nonn,base,more AUTHOR Labos Elemer, Jun 21 2004 EXTENSIONS More terms from Ryan Propper, Jun 13 2006 a(21)-a(23) from Ray Chandler, Jun 16 2006 a(24)-a(29) from Jon E. Schoenfield, Jul 22 2006 a(30) from Giovanni Resta, Apr 24 2017 a(31) from Bert Dobbelaere, Feb 22 2019 Offset corrected by Jon E. Schoenfield, Nov 25 2022 STATUS approved

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Last modified April 14 05:31 EDT 2024. Contains 371655 sequences. (Running on oeis4.)