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 A154528 Composites k such that (smallest digit of k) + (multiplicity of smallest digit of k) is an even composite. 0
 9, 22, 34, 35, 36, 38, 39, 44, 56, 57, 58, 63, 65, 66, 75, 78, 85, 87, 88, 93, 95, 111, 224, 225, 226, 228, 232, 242, 252, 262, 272, 282, 292, 322, 333, 344, 345, 346, 348, 354, 355, 356, 357, 358, 364, 365, 366, 368, 369, 374, 375, 376, 377, 378, 384, 385, 386 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS EXAMPLE 9 (composite) is a term because 9 + 1 = 10 (even composite); 22 (composite) is a term because 2 + 2 = 4 (even composite); 34 (composite) is a term because 3 + 1 = 4 (even composite). MAPLE frequdig := proc(n, dig) local f, d ; f := 0 ; for d in convert(n, base, 10) do if d = dig then f :=f+1; end if; end do; f ; end proc: A054054 := proc(n) min(op(convert(n, base, 10)) ) ; end proc: for n from 1 to 500 do c := A002808(n) ; sdg := A054054(c) ; a := sdg +frequdig(c, sdg) ; if type(a, 'even') and not isprime(a) then printf("%d, ", c ) ; end if; end do: # R. J. Mathar, May 05 2010 CROSSREFS Cf. A002808. Sequence in context: A228009 A330477 A295008 * A130861 A049730 A131895 Adjacent sequences:  A154525 A154526 A154527 * A154529 A154530 A154531 KEYWORD nonn,base AUTHOR Juri-Stepan Gerasimov, Jan 11 2009 EXTENSIONS Corrected (28 replaced with 38, 269 with 369) by R. J. Mathar, May 05 2010 Name and Example section edited by Jon E. Schoenfield, Feb 11 2019 STATUS approved

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Last modified July 31 04:01 EDT 2021. Contains 346367 sequences. (Running on oeis4.)