A280445 -id:A280445 - cp's OEIS frontend

A280446 Like A065759 but where f(n) = 2*n.

5848, 6884, 58480, 68840, 394062, 584800, 688400, 3940620, 5848000, 6884000, 39406200, 58480000, 68840000

Offset: 1

Paolo P. Lava, Jan 03 2017

Numbers of the form 5848*10^k, 6884*10^k, 394062*10^k, with k>=0, belong to the sequence.

			5848 = concat(5*848) = concat(58*48) = concat(584*8) and (5*848 + 58*48 + 584*8) = 11696 = 2*5848.

Cf. A065759, A280445, A280447.

P:=proc(q) local a,k,n; for n from 1 to q do a:=0;
for k from 1 to ilog10(n) do a:=a+(n mod 10^k)*trunc(n/10^k); od;
if a/n=2 then print(n); fi; od; end: P(10^9);

Select[Range[10^6], Function[n, Module[{a = {}, e = IntegerLength@ n - 1, k}, Do[AppendTo[a, # (n - #*10^(e - k)) &@ Floor[n/10^(e - k)]], {k, 0, e - 1}]; Total@ a] == 2 n]] (* Michael De Vlieger, Jan 04 2017 *)

A280447 Like A065759 but where f(n) = 3*n.

Original entry on oeis.org

176594, 281894, 371894, 446594, 1765940, 2818940, 2822594, 3718940, 3722594, 4465940, 17659400, 28189400, 28225940, 37189400, 37225940, 44659400

Offset: 1

Paolo P. Lava, Jan 03 2017

Numbers of the form 176594*10^k, 281894*10^k, 371894*10^k, 446594*10^k, etc., with k>=0, belong to the sequence.

			176594 = concat(1,76594) = concat(17,6594) = concat(176,594) = concat(1765,94) = concat(17659,4) and (1*76594 + 17*6594 + 176*594 + 1765*94 + 17659*4) = 529782 = 3*176594.

Cf. A065759, A280445, A280446.

P:=proc(q) local a,k,n; for n from 1 to q do a:=0;
for k from 1 to ilog10(n) do a:=a+(n mod 10^k)*trunc(n/10^k); od;
if a/n=3 then print(n); fi; od; end: P(10^9);

cp's OEIS Frontend

A280446 Like A065759 but where f(n) = 2*n.

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