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 A328200 Cubes of the form N^3 = concat(a,b,c) with N = a+b+c;  a, b, c > 0. 3
 512, 91125, 4181062131, 87824421125, 93824221184, 121213882349, 128711132649, 162324571375, 171323771464, 368910352448, 7890107061312, 171471879319616, 220721185826504, 470511577514952, 75460133084214033, 78330233506116032, 98316229404133819, 109294197946170875 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A variant of Kaprekar and pseudo-Kaprekar triples, cf. A006887 and A060768. Leading zeros as in A006887(4), 26198073 = (26 + 198 + 073)^3, are not allowed here. Even though this may be the most relevant sequence concerning this problem, we consider A328198 (sequence of the values N) as the main entry where all other information can be found. See also A328199 for the triples (a,b,c). LINKS Giovanni Resta, Table of n, a(n) for n = 1..239 Números y algo mas, 9 + 11 + 25 = 91125^(1/3) etc, post on facebook.com, Sep 30 2019. EXAMPLE 512^(1/3) = 8 = 5 + 1 + 2, 91125^(1/3) = 45 = 9 + 11 + 25, 4181062131^(1/3) = 1611 = 418 + 1062 + 131, ... PROG (PARI) is(n, Ln=A055642(n), n3=n^3, Ln3=A055642(n3))={my(ab, c); for(Lc=Ln3-2*Ln, Ln, [ab, c]=divrem(n3, 10^Lc); n-c<10^(Ln-1) || c < 10^(Lc-1) || for( Lb=Ln3-Ln-Lc, Ln, vecsum(divrem(ab, 10^Lb)) == n-c && ab%10^Lb>=10^(Lb-1)&& return(1)))} \\ A055642(n)=logint(n, 10)+1 = #digits(n) for( Ln=1, oo, for( n=10^(Ln-1), 10^Ln-1, is(n, Ln)&& print1(n^3", "))) CROSSREFS Cf. A328198 (values of N), A328199 (triples a,b,c), A006887 & A291461 (Kaprekar numbers), A060768 (pseudo Kaprekar numbers); A000578 (the cubes), A055642 (number of digits of n). Sequence in context: A013701 A187461 A291461 * A181244 A181252 A016749 Adjacent sequences:  A328197 A328198 A328199 * A328201 A328202 A328203 KEYWORD nonn,base AUTHOR M. F. Hasler, Oct 07 2019 STATUS approved

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Last modified December 4 13:29 EST 2021. Contains 349526 sequences. (Running on oeis4.)