The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A049304 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A049304

Numbers k such that k is a substring of 6^k.
(history; published version)

#24 by Joerg Arndt at Mon Feb 19 01:55:54 EST 2024

STATUS

editing

approved

#23 by Paolo P. Lava at Sun Feb 18 15:16:57 EST 2024

MAPLE

op(select(n->searchtext(convert(n, string), convert(6^n, string))>0, [$1..240])); # Paolo P. Lava, Sep 05 2018

STATUS

approved

editing

#22 by Susanna Cuyler at Sat Aug 14 18:54:09 EDT 2021

STATUS

proposed

approved

#21 by David A. Corneth at Fri Aug 13 10:11:17 EDT 2021

STATUS

editing

proposed

Discussion

Fri Aug 13

10:18

David A. Corneth: I like the jumps.

10:19

Jon E. Schoenfield: Thanks!

#20 by David A. Corneth at Fri Aug 13 10:11:13 EDT 2021

LINKS

David A. Corneth, <a href="/A049304/b049304.txt">Table of n, a(n) for n = 1..10000</a>

#19 by David A. Corneth at Fri Aug 13 10:05:22 EDT 2021

PROG

(PARI) is(n) = { my(digs6n, digsn, streak, i, j); digs6n = digits(6^n); digsn = digits(n); for(i = 1, #digs6n + 1 - #digsn, streak = 0; for(j = 1, #digsn, if(digs6n[i + j - 1] == digsn[j], streak++ , next(2) ) ); if(streak == #digsn, return(1) ) ); 0 } \\ David A. Corneth, Aug 13 2021

#18 by David A. Corneth at Fri Aug 13 09:39:20 EDT 2021

EXAMPLE

9 is in the sequence because 6^9 = 10077696 contains 9 as a substring. - David A. Corneth, Aug 13 2021

STATUS

proposed

editing

Discussion

Fri Aug 13

10:04

David A. Corneth: prog for formatting reasons is(n) = {
	my(digs6n, digsn, streak, i, j);
	digs6n = digits(6^n);
	digsn = digits(n); 
	for(i = 1, #digs6n + 1 - #digsn,
		streak = 0;
		for(j = 1, #digsn,
			if(digs6n[i + j - 1] == digsn[j],
				streak++
			,
				next(2)
			)
		);
		if(streak == #digsn,
			return(1)
		)
	); 
	0
}

#17 by Michael S. Branicky at Fri Aug 13 07:56:28 EDT 2021

STATUS

editing

proposed

#16 by Michael S. Branicky at Fri Aug 13 07:56:23 EDT 2021

PROG

(Python)

def ok(n): return str(n) in str(6**n)

print(list(filter(ok, range(241)))) # Michael S. Branicky, Aug 13 2021

STATUS

proposed

editing

#15 by Michel Marcus at Fri Aug 13 00:57:01 EDT 2021

STATUS

editing

proposed