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A217048 Semiprimes using only the curved digits 0, 3, 6, 8 and 9. 1
6, 9, 33, 38, 39, 69, 86, 93, 303, 309, 339, 386, 393, 398, 633, 669, 689, 698, 699, 803, 838, 866, 869, 886, 889, 893, 898, 899, 933, 939, 989, 993, 998, 3039, 3063, 3086, 3093, 3098, 3099, 3309, 3338, 3369, 3383, 3386, 3398, 3603, 3639, 3669, 3683, 3693 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This is to A079652 as semiprimes A001358 are to primes A000040.

LINKS

Table of n, a(n) for n=1..50.

FORMULA

A001358 INTERSECTION A072960.

EXAMPLE

a(41) = 3338 = 2 * 1669, the 938th semiprime.

PROG

(MAGMA) IsSemiprime:=func<n | &+[d[2]: d in Factorization(n)] eq 2>; [n: n in [2..3700] | IsSemiprime(n) and Intseq(n) subset [0, 3, 6, 8, 9]]; // Bruno Berselli, Sep 25 2012

CROSSREFS

Cf. A001358, A072960.

Sequence in context: A192425 A219687 A147415 * A105866 A267690 A084007

Adjacent sequences:  A217045 A217046 A217047 * A217049 A217050 A217051

KEYWORD

nonn,base,easy

AUTHOR

Jonathan Vos Post, Sep 25 2012

STATUS

approved

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Last modified November 21 04:22 EST 2019. Contains 329350 sequences. (Running on oeis4.)