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A320930 Numbers n such that 4^n starts with n. 0
10, 17, 556, 1771, 4695, 38537, 56969, 345797, 141419115, 1788191728 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

4^10 = 1048576 starts with 10, so 10 is in the sequence.

MAPLE

filter:= proc(n) local t, b;

  t:= 4^n;

b:= ilog10(t) - ilog10(n);

floor(t/10^b) = n

end proc:

select(filter, [$1..10^5]);

CROSSREFS

Cf. A100129, A288845.

Sequence in context: A177185 A241281 A002744 * A337325 A156382 A214894

Adjacent sequences:  A320927 A320928 A320929 * A320931 A320932 A320933

KEYWORD

nonn,base,more

AUTHOR

Robert Israel, Oct 24 2018

EXTENSIONS

a(8)-a(10) from Giovanni Resta, Oct 25 2018

STATUS

approved

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Last modified May 9 18:53 EDT 2021. Contains 343744 sequences. (Running on oeis4.)