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A080035 "Orderly" Friedman numbers (or "good" Friedman numbers): Friedman numbers (A036057) where the construction digits are used in the proper order. 7
127, 343, 736, 1285, 2187, 2502, 2592, 2737, 3125, 3685, 3864, 3972, 4096, 6455, 11264, 11664, 12850, 13825, 14641, 15552, 15585, 15612, 15613, 15617, 15618, 15621, 15622, 15623, 15624, 15626, 15632, 15633, 15642, 15645, 15655, 15656 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Primes in this sequence are listed in A252483. The subsequence A156954 is a "simplified" variant where no parentheses, unary operations (negation) nor concatenation is allowed. - M. F. Hasler, Jan 07 2015
REFERENCES
Credit goes to Mike Reid (Brown University) and Eric Friedman (Stetson University).
Colin Rose, "Radical Narcissistic numbers", J. Recreational Mathematics, vol. 33, (2004-2005), pp. 250-254. See page 251.
LINKS
M. Brand, Friedman numbers have density 1, Discrete Applied Mathematics, Volume 161, Issues 16-17, November 2013, Pages 2389-2395.
Ed Copeland and Brady Haran, Friedman numbers, Numberphile video, 2014
Eric Friedman, Friedman Numbers.
EXAMPLE
127 = -1 + 2^7, 343 = (3 + 4) ^ 3, 736 = 7 + 3^6, etc.
The 4th "orderly" Freidman number is 1285 = (1 + 2^8) * 5.
CROSSREFS
Cf. A036057.
Sequence in context: A142165 A031933 A283622 * A162004 A112419 A142201
KEYWORD
nonn,base,nice
AUTHOR
David Rattner (david_rattner(AT)prusec.com), Mar 14 2003
EXTENSIONS
More terms from Alonso del Arte, Aug 25 2004
Edited by M. F. Hasler, Jan 07 2015
STATUS
approved

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Last modified April 18 18:58 EDT 2024. Contains 371781 sequences. (Running on oeis4.)