Number of increasing arithmetic progressions in {1,2,3,...,n}, including trivial arithmetic progressions of lengths 1 and 2.
A051336
Number of increasing arithmetic progressions in {1,2,3,...,n}, including trivial arithmetic progressions of lengths 1 and 2.
Terms
- a(0) =1a(1) =3a(2) =7a(3) =13a(4) =22a(5) =33a(6) =48a(7) =65a(8) =86a(9) =110a(10) =138a(11) =168a(12) =204a(13) =242a(14) =284a(15) =330a(16) =381a(17) =434a(18) =493a(19) =554a(20) =621a(21) =692a(22) =767a(23) =844a(24) =929a(25) =1017a(26) =1109a(27) =1205a(28) =1307a(29) =1411
External references
- oeis: A051336