A374308
Integers m, with k digits, such that m = Sum_{i=1..k} A000203(m without its i-th digit).
Original entry on oeis.org
136, 10974, 96672, 227358, 455334, 527254, 947886
Offset: 1
136 is in the sequence as 136 = sigma(36) + sigma(16) + sigma(13) = 91 + 31 + 14. - _David A. Corneth_, Jul 27 2024
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with(numtheory): P:=proc(q) local a,d,k,i,n,t;
for n from 1 to q do t:=0; a:=convert(n,base,10);
for k from 1 to nops(a) do d:=0;
for i from 1 to nops(a) do if i<> k then d:=d*10+a[-i]; fi; od; t:=sigma(d)+t; od;
if n=t then print(n); fi; od; end: P(10^6)
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q[n_] := Module[{d = IntegerDigits[n]}, n == Total[DivisorSigma[1, Map[FromDigits, Delete[d, #] & /@ Range[Length[d]]]]]]; Select[Range[10^6], q] (* Amiram Eldar, Jul 27 2024 *)
A374309
Integers m, with k digits, such that m = Sum_{i=1..k} A001065(m without its i-th digit).
Original entry on oeis.org
17940, 159504, 1180140, 2607408, 3478008, 58039388, 111975864, 169084882, 382009288, 942525448, 2014102784, 4978124388, 7360873684
Offset: 1
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with(numtheory): P:=proc(q) local a,d,k,i,n,t;
for n from 1 to q do t:=0; a:=convert(n,base,10);
for k from 1 to nops(a) do d:=0; for i from 1 to nops(a) do
if i<> k then d:=d*10+a[-i]; fi; od; t:=sigma(d)-d+t; od;
if n=t then print(n); fi; od; end: P(10^7)
A374368
Integers m, with k digits, such that m = Sum_{i=1..k} A003415(m without its i-th digit).
Original entry on oeis.org
42080, 150922, 301280, 945688, 1014004, 4962140
Offset: 1
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with(numtheory): P:=proc(q) local a,d,i,k,n,p,t;
for n from 1 to q do t:=0; a:=convert(n,base,10); for k from 1 to nops(a) do
d:=0; for i from 1 to nops(a) do if i<> k then d:=d*10+a[-i]; fi; od;
t:=d*add(op(2, p)/op(1, p),p=ifactors(d)[2])+t; od;
if n=t then print(n); fi; od; end: P(10^7);
Showing 1-3 of 3 results.
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