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 A257085 Numbers n such that the decimal expansions of both n and n^2 only use the digits 0..6. 3
 0, 1, 2, 4, 5, 6, 10, 11, 12, 15, 16, 20, 21, 25, 32, 34, 35, 40, 45, 46, 50, 51, 55, 56, 60, 65, 66, 100, 101, 102, 105, 106, 110, 111, 112, 115, 116, 120, 121, 125, 142, 145, 146, 150, 152, 155, 156, 160, 162, 200, 201, 204, 205, 206, 210, 211, 215, 216, 225, 231, 235, 245, 246, 250, 251, 252, 254, 255, 256 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS Danny Rorabaugh, Table of n, a(n) for n = 1..10000 EXAMPLE 116 is in the list because 116 and 116^2 = 13456 do not use the digits 7, 8 or 9. 182 is not in the list because it uses the digit 8 (even though 182^2 = 33124 would be fine). 253 is not in the list because 253^2 = 6409 uses the digit 9. MATHEMATICA Select[Range@ 256, Total@ Take[DigitCount[#], {7, 9}] == 0 && Total@ Take[DigitCount[#^2], {7, 9}] == 0 &] (* Michael De Vlieger, Apr 17 2015 *) PROG (PARI) isok(n) = ((vecmax(digits(n)) <= 6) && (vecmax(digits(n^2)) <= 6)) || (n==0); \\ Michel Marcus, Feb 02 2016 CROSSREFS Cf. A178501 (0..1), A136808(0..2), A136809(0..3), A136810 (0..4), A257086 (0..5). Cf. A136859, A256633. Sequence in context: A348937 A117890 A108853 * A334736 A265349 A047433 Adjacent sequences: A257082 A257083 A257084 * A257086 A257087 A257088 KEYWORD nonn,easy,base AUTHOR Danny Rorabaugh, Apr 15 2015 STATUS approved

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Last modified September 13 07:00 EDT 2024. Contains 375865 sequences. (Running on oeis4.)