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 A161551 The smallest composite number larger than the n-th composite number, which has a sum of digits equal to the n-th composite number. 2
 22, 15, 26, 18, 28, 39, 68, 69, 88, 99, 299, 399, 589, 699, 799, 899, 999, 2899, 3999, 5999, 6999, 7999, 9899, 9999, 29999, 39999, 58999, 69999, 89999, 99999, 299899, 399999, 499999, 689999, 699999, 889999, 999999, 1999999, 3899999, 3999999 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Variant of A073866, where the requirement that a(n) > A002808(n) is dropped. LINKS FORMULA min{c in A002808, c> A002808(n): A007953(c) = A002808(n)}. - R. J. Mathar, Dec 06 2011 EXAMPLE The first composite is 4, and the first sum of digits is 13, but since that is prime, we go to the next, 22, which being composite is a(1). MAPLE A161551 := proc(n)     for j from n+1 do         if digsum(A002808(j)) = A002808(n) then             return A002808(j) ;         end if;     end do: end proc: seq(A161551(n), n=1..30) ; # R. J. Mathar, Dec 06 2011 PROG (UBASIC) 10 'compsdig, Enoch Haga, Jun 12 2009 20 N=1 30 Q=str(N) 40 L=len(Q) 50 for X=1 to L 60 M=str(mid(Q, X, 1)): Z=Z+val(mid(Q, X, 1)) 70 next X 80 if Z=56 and Z<>prmdiv(Z) and N<>prmdiv(N) then print N: stop 90 Z=0: N=N+1: goto 30 CROSSREFS Cf. A075360, A054750. Sequence in context: A040464 A266015 A070665 * A291428 A195927 A195930 Adjacent sequences:  A161548 A161549 A161550 * A161552 A161553 A161554 KEYWORD base,easy,nonn AUTHOR Enoch Haga, Jun 13 2009 STATUS approved

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Last modified December 11 21:25 EST 2019. Contains 329937 sequences. (Running on oeis4.)