A067110 a(n) = floor(concatenation of first n primes / sum of first n primes).

1, 4, 23, 138, 8418, 574905, 40639850, 3061183528, 235711131719, 18272180753428, 1473194573245205, 119650320669661386, 9903829063833316444, 838829650246380538698, 71863149914400283955531

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..100

Example

a(4) = floor(2357/17) = floor(138.647058823529411764705882352941) = 138.

Mathematica

f[n_] := (a = {}; k = 1; While[ k < n + 1, a = Join[a, IntegerDigits[ Prime[k]]]; k++ ]; FromDigits[a]); Table[ Floor[ f[n]/Sum[ Prime[i], {i, 1, n} ]], {n, 1, 20} ]

Prog

(PARI) digitsIn(x)= { local(d); if (x==0, return(1)); d=1 + log(x)\log(10); if (10^d == x, d++, if (10^(d-1) > x, d--)); return(d) } Concat(a, b)= { return(a*10^digitsIn(b) + b) } { c=0; s=0; for (n=1, 100, p=prime(n); s+=p; c=Concat(c, p); write("b067110.txt", n, " ", floor(c/s)) ) } \\ Harry J. Smith, May 22 2010

Crossrefs

Cf. A007504, A019518.

Sequence in context: A302761 A091640 A237362 * A290052 A158197 A356282

Adjacent sequences: A067107 A067108 A067109 * A067111 A067112 A067113

Keyword

easy,nonn,base

Author

Amarnath Murthy, Jan 08 2002

Extensions

More terms from Robert G. Wilson v, Jan 08 2002

Edited by Charles R Greathouse IV, Apr 28 2010

Status

approved