A131937 a(1)=1; a(2)=4. a(n) = a(n-1) + (n-th positive integer which does not occur in sequence A131938).

1, 4, 8, 14, 21, 29, 38, 49, 61, 74, 88, 103, 120, 138, 157, 177, 198, 220, 244, 269, 295, 322, 350, 379, 409, 440, 473, 507, 542, 578, 615, 653, 692, 732, 773, 816, 860, 905, 951, 998, 1046, 1095, 1145, 1196, 1248, 1302, 1357, 1413, 1470, 1528, 1587, 1647

Offset

1,2

Links

Table of n, a(n) for n=1..52.

Example

A131938: 2,5,10,16,23,32,42,53,...
Positive integers not in A131938: 1,3,4,6,7,8,9,11,...
So A131937(8) = A131937(7) + 11 = 49.

Crossrefs

Cf. A131938.

Sequence in context: A312697 A312698 A312699 * A183857 A088804 A374505

Adjacent sequences: A131934 A131935 A131936 * A131938 A131939 A131940

Keyword

nonn

Author

Leroy Quet, Jul 30 2007

Extensions

More terms from Farideh Firoozbakht, Aug 07 2007

a(51)-a(52) from Ray Chandler, Mar 06 2010

Status

approved