A071855 Numbers n such that A067434(n) = A000720(n) + A000005(n).

1, 37, 41, 43, 47, 49, 58, 65, 69, 81, 85, 92, 128, 130, 135, 136, 154, 184, 208, 220, 228, 450, 540, 840

Offset: 1

Author

Benoit Cloitre, Jun 09 2002

Keywords

• nonn

Comments

No further terms below 143260.

No further terms below 2*10^4. - Robert G. Wilson v

Programs

Mathematica

Select[ Range[10^3], Length[ FactorInteger[ Binomial[2#, # ]]] == PrimePi[ # ] + DivisorSigma[0, # ] & ]

PARI

for(n=1,1000,if(omega(binomial(2*n,n))=sum(i=1,n,isprime(i))+numdiv(n),print1(n,",")))