A182140 Numbers n such that A060968(n) = A201629(n).

2, 3, 5, 7, 11, 13, 15, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 143, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 255, 257

Offset: 1

Author

José María Grau Ribas, Apr 14 2012

Keywords

• nonn

Comments

Includes prime numbers and the sequence A071700.

a(n) = A240960(n) for n <= 35. - Reinhard Zumkeller, Aug 05 2014

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A060968, A201629, A071700, A240960.

Programs

Haskell

a182140 n = a182140_list !! (n-1)
a182140_list = [x | x <- [1..], a060968 x == a201629 x]
-- Reinhard Zumkeller, Aug 05 2014

Mathematica

fa = FactorInteger; A060968[p_, s_] := Which[Mod[p, 4] == 1, p^( s - 1)*(p - 1), Mod[p, 4] == 3, p^(s - 1)*(p + 1), s == 1,2, True, 2^(s + 1)]; A060968[1] = 1; A060968[n_] := Product[A060968[fa[n][[i, 1]], fa[n][[i, 2]]], {i, Length[fa[n]]}]; A201629[n_] := Which[Mod[n, 4] == 1, (n - 1), Mod[n, 4] == 3, (n + 1), True, n]; Select[Range[1000], A060968[#] == A201629[#] &]

PARI

is(n)=my(f=factor(n)[, 1]); n*prod(i=if(n%2, 1, 2), #f, if(f[i]%4==1, 1-1/f[i], 1+1/f[i]))*if(n%4, 1, 2)==if(n%2,(n+1)\4*4,n) \\ Charles R Greathouse IV, Jul 03 2013