The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A025616 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A025616

Numbers of form 3^i*10^j, with i, j >= 0.
(history; published version)

#17 by Vaclav Kotesovec at Fri Sep 25 06:02:59 EDT 2020

STATUS

editing

approved

#16 by Vaclav Kotesovec at Fri Sep 25 06:02:55 EDT 2020

FORMULA

a(n) ~ exp(sqrt(2*log(3)*log(10)*n)) / sqrt(30). - Vaclav Kotesovec, Sep 25 2020

STATUS

approved

editing

#15 by Joerg Arndt at Fri Sep 25 04:34:57 EDT 2020

STATUS

reviewed

approved

#14 by Michel Marcus at Fri Sep 25 04:24:45 EDT 2020

STATUS

proposed

reviewed

#13 by Amiram Eldar at Fri Sep 25 04:20:18 EDT 2020

STATUS

editing

proposed

#12 by Amiram Eldar at Fri Sep 25 04:13:57 EDT 2020

MATHEMATICA

n = 10^6; Flatten[Table[3^i*10^j, {i, 0, Log[3, n]}, {j, 0, LogLog10[10, n/3^i]}]] // Sort (* Amiram Eldar, Sep 25 2020 *)

#11 by Amiram Eldar at Fri Sep 25 03:24:45 EDT 2020

FORMULA

Sum_{n>=1} 1/a(n) = (3*10)/((3-1)*(10-1)) = 5/3. - Amiram Eldar, Sep 25 2020

MATHEMATICA

n = 10^6; Flatten[Table[3^i*10^j, {i, 0, Log[3, n]}, {j, 0, Log[10, n/3^i]}]] // Sort (* Amiram Eldar, Sep 25 2020 *)

STATUS

approved

editing

#10 by Charles R Greathouse IV at Wed Jan 10 12:32:32 EST 2018

STATUS

editing

approved

#9 by Charles R Greathouse IV at Wed Jan 10 12:31:59 EST 2018

PROG

(PARI) list(lim)=my(v=List(), N); for(n=0, logint(lim\=1, 10), N=10^n; while(N<=lim, listput(v, N); N*=3)); Set(v) \\ Charles R Greathouse IV, Jan 10 2018

STATUS

approved

editing

#8 by Reinhard Zumkeller at Fri May 15 16:53:25 EDT 2015

STATUS

editing

approved