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A061371 Composite numbers with all prime digits. 5
22, 25, 27, 32, 33, 35, 52, 55, 57, 72, 75, 77, 222, 225, 232, 235, 237, 252, 253, 255, 272, 273, 275, 322, 323, 325, 327, 332, 333, 335, 352, 355, 357, 372, 375, 377, 522, 525, 527, 532, 533, 535, 537, 552, 553, 555, 572, 573, 575, 722, 723, 725, 732, 735 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

T. D. Noe, Table of n, a(n) for n = 1..1000

EXAMPLE

a(5) = 35 is composite with digits 3 and 5 which are primes.

22 is nonprime and has prime digits, twice 2;

573 is nonprime and has prime digits, 3, 5 and 7.

MAPLE

stev_sez:=proc(n) local i, tren, st, ans, anstren; ans:=[ ]: anstren:=[ ]: tren:=n: for i while (tren>0) do st:=round( 10*frac(tren/10) ): ans:=[ op(ans), st ]: tren:=trunc(tren/10): end do; for i from nops(ans) to 1 by -1 do anstren:=[ op(anstren), op(i, ans) ]; od; RETURN(anstren); end:

ts_stnepf:=proc(n) local i, stpf, ans; ans:=stev_sez(n): stpf:=0: for i from 1 to nops(ans) do if (isprime(op(i, ans))='false') then stpf:=stpf+1; # number of nonprime digits fi od; RETURN(stpf) end:

ts_nepr_neprn0:=proc(n) local i, stpf, ans, ans1, tren; ans:=[ ]: stpf:=0: tren:=1: for i from 1 to n do if ( isprime(i)='false' and ts_stnepf(i) = 0) then ans:=[ op(ans), i ]: tren:=tren+1; fi od; RETURN(ans) end: ts_nepr_neprn0(4000); # Jani Melik, Apr 11 2004

MATHEMATICA

With[{comps=Complement[Range[1000], Prime[Range[PrimePi[1000]]]]}, Select[ comps, And@@PrimeQ[IntegerDigits[#]]&]] (* Harvey P. Dale, Dec 21 2011 *)

Table[Select[FromDigits/@Tuples[{2, 3, 5, 7}, n], CompositeQ], {n, 2, 4}]//Flatten (* Harvey P. Dale, Oct 05 2019 *)

PROG

(MAGMA) [ n: n in [22..736] | not IsPrime(n) and Set(Intseq(n)) subset [2, 3, 5, 7] ];  // Bruno Berselli, Dec 21 2011

CROSSREFS

Cf. A061372.

Sequence in context: A066737 A121609 A092631 * A254753 A070809 A280646

Adjacent sequences:  A061368 A061369 A061370 * A061372 A061373 A061374

KEYWORD

nonn,base

AUTHOR

Amarnath Murthy, May 02 2001

EXTENSIONS

Corrected and extended by Larry Reeves (larryr(AT)acm.org), May 08 2001

STATUS

approved

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Last modified November 18 07:22 EST 2019. Contains 329252 sequences. (Running on oeis4.)