A112040 Terms in A112039 that are divisible by 3, divided by 3.

1, 3, 7, 13, 33, 47, 132, 458, 777, 853, 3845, 4395, 4783, 4983, 6038, 6487, 6719, 6957, 11707, 12030, 12688, 13025, 13365, 13709, 14057, 14409, 15861, 17789, 18598, 19008, 19845, 20272, 20702, 21135, 21570, 22010, 22458, 23378, 23850, 24326

Offset

1,2

Comments

These integers also form a kind of prime with the a[2*n]/3 as a discriminant. dd = Flatten[Table[If[IntegerQ[a[2*n]/3] == True, Prime[n], {}], {n, 1, 200}]] 2, 3, 5, 7, 13, 17, 31, 67, 89, 97, 227, 239, 251, 257, 281, 293, 307, 311, 419, 421, 433, 439, 443, 449, 457, 461, 487, 521, 541, 547, 563, 569, 571, 577, 587, 593, 599, 607, 613, 617, 641, 643, 647, 653, 673, 743, 751, 769, 853, 857, 859, 863, 877, 881, 911, 919, 929, 947, 953, 967, 977, 983, 991, 997, 1009, 1031, 1039, 1063

Links

Table of n, a(n) for n=1..40.

Formula

a(0)=1/2 a(n) = a(n-1) + Prime[n]/2 if a[2*n]/3 is an Integer then aout=a[2*n]/3

Mathematica

a[0] = 1/2; a[n_] := a[n] = a[n - 1] + Prime[n]/2 cc = Flatten[Table[If[IntegerQ[a[2*n]/3] == True, a[2*n]/3, {}], {n, 1, 200}]]

Crossrefs

Sequence in context: A292448 A222227 A152981 * A358560 A222187 A084611

Adjacent sequences: A112037 A112038 A112039 * A112041 A112042 A112043

Keyword

nonn

Author

Roger L. Bagula, Nov 28 2005

Status

approved