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 A230103 Number of m such that m + (product of digits of m) equals n. 6
 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 2, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 2, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 3, 0, 0, 0, 1, 1, 1, 0, 1, 0, 2, 0, 2, 0, 0, 1, 1, 1, 1, 0, 2, 0, 0, 0, 2, 1, 0, 0, 1, 0, 3, 1, 0, 0, 0, 1, 2, 0, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 2, 0, 2, 1, 3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,11 COMMENTS Number of times n appears in A230099. LINKS Michel Marcus, Table of n, a(n) for n = 0..10000 Index entries for Colombian or self numbers and related sequences MAPLE # Maple code for A230099, A230103, A230104, A230105 with(LinearAlgebra): read transforms; # to get digprod M:=1000; lis1:=Array(0..M); lis2:=Array(0..M); ctmax:=4; for i from 0 to ctmax do ct[i]:=Array(0..M); od: for n from 0 to M do m:=n+digprod(n); lis1[n]:=m; if (m <= M) then lis2[m]:=lis2[m]+1; fi; od: t1:=[seq(lis1[i], i=0..M)]; # A230099 t2:=[seq(lis2[i], i=0..M)]; # A230103 COMPl(t1); # A230104 for i from 1 to M do h:=lis2[i]; if h <= ctmax then ct[h]:=[op(ct[h]), i]; fi; od: len:=nops(ct[0]); [seq(ct[0][i], i=1..len)]; # A230104 again len:=nops(ct[1]); [seq(ct[1][i], i=1..len)]; # A230105 PROG (PARI) a(n) = if (n==0, return(1)); sum(k=1, n, k+vecprod(digits(k)) == n); \\ Michel Marcus, Sep 18 2020 (Python) from math import prod def b(n): return n + prod(map(int, str(n))) def a(n): return sum(1 for m in range(n+1) if b(m) == n) print([a(n) for n in range(103)]) # Michael S. Branicky, Jan 09 2023 (Python) # faster version for initial segment of sequence from math import prod from collections import Counter def b(n): return n + prod(map(int, str(n))) def aupto(n): c = Counter(b(m) for m in range(n+1)) return [c[k] for k in range(n+1)] print(aupto(102)) # Michael S. Branicky, Jan 09 2023 CROSSREFS Cf. A230099, A230104. Sequence in context: A096972 A101227 A277162 * A267602 A021499 A176742 Adjacent sequences: A230100 A230101 A230102 * A230104 A230105 A230106 KEYWORD nonn,base AUTHOR N. J. A. Sloane, Oct 13 2013 STATUS approved

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Last modified May 26 16:43 EDT 2024. Contains 372840 sequences. (Running on oeis4.)