A380923 Integers k such that k = Sum k/(p_i + j), where p_i are the prime factors of k (with multiplicity). Case j = -3.

25, 245, 1250, 2401, 4235, 12250, 41503, 62500, 73205, 120050, 136045, 138985, 211750, 215215, 612500, 717409, 1176490, 1333241, 1362053, 1856465, 2075150, 2109107, 2351635, 2402455, 3125000, 3660250, 3720145, 4561235, 5330605, 5535985, 6002500, 6802250, 6949250

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

138985 = 5*7*11*19^2 = 138985/(5-3) +138985/(7-3) +138985/(11-3) +138985*2/(19-3)

Maple

with(numtheory): P:=proc(q, h) global k, n, v; v:=[];
for n from 1 to q do if n mod 3>0 then if n=add(n*k[2]/(k[1]+h), k=ifactors(n)[2]) then v:=[op(v), n];
print(n); fi; fi; od; op(v); end: P(6949250, -3);

Crossrefs

Cf. A380888, A380889, A380900, A380901, A380924 - A380928.

Sequence in context: A294290 A352304 A362393 * A107943 A125388 A126546

Adjacent sequences: A380919 A380920 A380921 * A380924 A380925 A380926

Keyword

nonn,easy,new

Author

Paolo P. Lava, Mar 03 2025

Status

approved