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 A077680 Squarefree numbers beginning with 4. 12
 41, 42, 43, 46, 47, 401, 402, 403, 406, 407, 409, 410, 411, 413, 415, 417, 418, 419, 421, 422, 426, 427, 429, 430, 431, 433, 434, 435, 437, 438, 439, 442, 443, 445, 446, 447, 449, 451, 453, 454, 455, 457, 458, 461, 462, 463, 465, 466, 467, 469, 470, 471, 473 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Lower density is 3/(20*Pi^2), upper density is 4/(3*Pi^2). - Charles R Greathouse IV, Nov 05 2017 LINKS Amiram Eldar, Table of n, a(n) for n = 1..10000 MATHEMATICA Select[Range[499], First[IntegerDigits[#]]==4&&SquareFreeQ[#]&] (* Harvey P. Dale, Apr 24 2018 *) PROG (PARI) is(n)=n>40 && digits(n)[1]==4 && issquarefree(n) \\ Charles R Greathouse IV, Nov 05 2017 CROSSREFS Intersection of A005117 and A217397. Cf. A077677, A077678, A077679, A077681, A077682, A077683, A077684, A077685. Sequence in context: A191754 A165862 A339568 * A283598 A041839 A098064 Adjacent sequences: A077677 A077678 A077679 * A077681 A077682 A077683 KEYWORD base,easy,nonn AUTHOR Amarnath Murthy, Nov 16 2002 EXTENSIONS More terms from Sascha Kurz, Jan 28 2003 STATUS approved

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Last modified December 7 18:28 EST 2023. Contains 367660 sequences. (Running on oeis4.)