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A062837 Numbers n such that n, 2n+1, 3n+1 are all squarefree. 0
2, 3, 6, 7, 10, 11, 14, 15, 19, 23, 26, 30, 34, 35, 38, 39, 42, 43, 46, 47, 51, 55, 59, 66, 70, 71, 74, 78, 79, 82, 86, 91, 95, 102, 106, 107, 110, 111, 115, 118, 119, 123, 127, 131, 134, 138, 142, 143, 146, 151, 154, 155, 159, 167, 170, 174, 178, 179, 182, 186 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..60.

MATHEMATICA

Select[Range[200], AllTrue[{#, 2#+1, 3#+1}, SquareFreeQ]&]  (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 20 2014 *)

PROG

(PARI) j=[]; for(n=1, 200, if(issquarefree(n) && issquarefree(2*n+1) && issquarefree(3*n+1), j=concat(j, n))); j

CROSSREFS

Cf. A005117.

Sequence in context: A053438 A042964 A230375 * A190670 A226115 A073170

Adjacent sequences:  A062834 A062835 A062836 * A062838 A062839 A062840

KEYWORD

nonn

AUTHOR

Jason Earls, Jul 21 2001

STATUS

approved

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Last modified October 16 03:37 EDT 2019. Contains 328040 sequences. (Running on oeis4.)