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 A320861 Powers of 2 with initial digit 5. 5
 512, 524288, 536870912, 549755813888, 562949953421312, 576460752303423488, 590295810358705651712, 5070602400912917605986812821504, 5192296858534827628530496329220096, 5316911983139663491615228241121378304, 5444517870735015415413993718908291383296 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Robert Israel, Table of n, a(n) for n = 1..263 Index to divisibility sequences MAPLE select(x->"5"=""||x[1], [2^n\$n=0..160])[]; # Alternative: Res:= NULL: count:= 0: for k from 1 to 49 do n:= ilog2(6*10^k); if n > ilog2(5*10^k) then count:= count+1; Res:= Res, 2^n; fi od: Res; # Robert Israel, Oct 26 2018 MATHEMATICA Select[2^Range[200], First[IntegerDigits[#]]==5 &] (* Vincenzo Librandi, Oct 25 2018 *) PROG (GAP) Filtered(List([0..160], n->2^n), i->ListOfDigits(i)[1]=5); (PARI) lista(nn) = {for(n=1, nn, x = 2^n; if (digits(x=2^n)[1] == 5, print1(x, ", ")); ); } \\ Michel Marcus, Oct 25 2018 (Magma) [2^n: n in [1..200] | Intseq(2^n)[#Intseq(2^n)] eq 5]; // Vincenzo Librandi, Oct 25 2018 CROSSREFS Cf. A000079 (powers of 2), A008952 (leading digit of 2^n). Powers of 2 with initial digit k, (k = 1..5): A067488, A067480, A320859, A320860, this sequence. Sequence in context: A181252 A016749 A144323 * A347858 A220303 A323542 Adjacent sequences: A320858 A320859 A320860 * A320862 A320863 A320864 KEYWORD base,nonn AUTHOR Muniru A Asiru, Oct 23 2018 STATUS approved

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Last modified December 9 03:28 EST 2023. Contains 367681 sequences. (Running on oeis4.)