Original entry on oeis.org
5848, 6884, 58480, 68840, 394062, 584800, 688400, 3940620, 5848000, 6884000, 39406200, 58480000, 68840000
Offset: 1
5848 = concat(5*848) = concat(58*48) = concat(584*8) and (5*848 + 58*48 + 584*8) = 11696 = 2*5848.
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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);
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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 *)
Original entry on oeis.org
176594, 281894, 371894, 446594, 1765940, 2818940, 2822594, 3718940, 3722594, 4465940, 17659400, 28189400, 28225940, 37189400, 37225940, 44659400
Offset: 1
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.
A265737
Consider any concatenation of the type n = concat(a,b). Sequence lists numbers that are the sum of the products of some of such couples a and b.
Original entry on oeis.org
655, 1064, 1258, 1461, 1642, 2361, 2464, 3382, 3442, 3835, 4738, 4925, 5275, 6208, 6550, 8291, 9274, 10640, 11197, 11548, 11593, 12508, 12580, 12915, 13706, 14610, 16420, 16625, 17184, 18232, 19641, 23610, 24640, 31714, 33820, 34420, 36226, 38350, 39826, 40722
Offset: 1
For 655 we have: 6 * 55 = 320, 65 * 5 = 325 and 320 + 325 = 665.
For 1064 we have: 10 * 64 = 640, 106 * 4 = 424 and 640 + 424 = 1064.
For 41464 we have: 4 * 1464 = 5856, 41 * 464 = 19024, 4146 * 4 = 16584 and 5856 + 19024 + 16584 = 41464.
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with(combinat): P:=proc(q) local a,j,k,n; for n from 1 to q do a:={};
for k from 1 to ilog10(n) do a:=a union {(n mod 10^k)*trunc(n/10^k)}; od; a:=choose(a);
for k from 2 to nops(a) do if n=add(a[k][j],j=1..nops(a[k])) then print(n); break; fi; od;
od; end: P(10^9);
Showing 1-3 of 3 results.
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