A238697 Quotients connected with the Banach matchboxes problem: Sum_{i=1..prime(n)-7} 2^(i-1)*binomial(i+2,3)/prime(n) (case 3).

0, 19, 197, 10481, 64027, 1980327, 259179061, 1257208799, 131286703021, 2756321451033, 12473384091267, 250290955437775, 21588599628845597, 1792050990708087027, 7763319803561678613, 620323392829436218475, 11365013042482773469559, 48487140450183407727097

Offset

4,2

Comments

See comment in A238693.

Links

Table of n, a(n) for n=4..21.

V. Shevelev, Banach matchboxes problem and a congruence for primes, arXiv:1110.5686 [math.HO], 2011.

Mathematica

Array[Sum[2^(i - 1)*Binomial[i + 2, 3]/#, {i, # - 7}] &@ Prime@ # &, 18, 4] (* Michael De Vlieger, Dec 06 2018 *)

Prog

(PARI) a(n) = sum(i=1, prime(n)-7, 2^(i-1)*binomial(i+2, 3))/prime(n); \\ Michel Marcus, Dec 06 2018

Crossrefs

Cf. A238693.

Sequence in context: A141995 A210339 A097445 * A256639 A058370 A230012

Adjacent sequences: A238694 A238695 A238696 * A238698 A238699 A238700

Keyword

nonn

Author

Vladimir Shevelev, Mar 03 2014

Extensions

More terms from Peter J. C. Moses, Mar 03 2014

Status

approved