A129091 a(0)=1; a(n) = gcd(a(n-1), n) + lcm(a(n-1), n).

1, 2, 4, 13, 53, 266, 800, 5601, 44809, 403282, 2016412, 22180533, 88722135, 1153387756, 8073714294, 40368571473, 645897143569, 10980251440674, 32940754322028, 625874332118533, 12517486642370661, 12517486642370682

Offset: 0

Author

Leroy Quet, Mar 29 2007

Keywords

• nonn

Crossrefs

Cf. A129090.

Programs

Maple

a[0]:=1: for n from 1 to 25 do a[n]:=gcd(a[n-1],n)+lcm(a[n-1],n) od: seq(a[n],n=0..25); # Emeric Deutsch, Apr 02 2007

Extensions

More terms from Emeric Deutsch, Apr 02 2007