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A274116 (1+e)-sigma amicable numbers. 2
220, 284, 366, 378, 2620, 2924, 3864, 4584, 5020, 5564, 16104, 16536, 16632, 16728, 26448, 28752, 29760, 30912, 43524, 53692, 63020, 67344, 69552, 69615, 76084, 87633, 100485, 122265, 124155, 139815, 142290, 142310, 168730, 179118, 196248, 196724, 198990, 202444 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The first time a pair ordered by its first element is not adjacent is x = 16104, y = 16632 which correspond to a(11) and a(13), respectively.

LINKS

Paolo P. Lava, Table of n, a(n) for n = 1..500

EXAMPLE

(1+e)-sigma(366) = 378 and (1+e)-sigma(378) = 366.

MAPLE

with(numtheory): T:=proc(n) local a, d, p, e, s, sp; a:=1;

for d in ifactors(n)[2] do p:=op(1, d); e:= op(2, d); sp:=1;

for s in divisors(e) do sp:=sp+p^s; od: a:=a*sp; od: a; end:

P:=proc(q) local n, x, y; for n from 1 to q do x:=T(n)-n; y:=T(x)-x;

if n=y and x<>y then print(n); fi; od; end: P(10^10);

CROSSREFS

Cf. A049603, A051378, A274118.

Sequence in context: A064477 A217160 A203777 * A121507 A255215 A063990

Adjacent sequences:  A274113 A274114 A274115 * A274117 A274118 A274119

KEYWORD

nonn,easy

AUTHOR

Paolo P. Lava, Jun 10 2016

STATUS

approved

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Last modified December 14 00:21 EST 2017. Contains 295976 sequences.