A103734 Negative of column k=7 sequence of array A103728.

109, 731, 10767, 30149, 163129, 1143211, 1970129, 8122067, 18188839, 26350925, 52385857, 131260323, 295577917, 379875659, 767165717, 1181890569, 1452930119, 2608460321, 3755952517, 6277007703, 11796314207, 15849070099, 18287662313

Offset

0,1

Comments

The two a(n) formulas, given below, produce natural numbers for all n>=0.

Links

Table of n, a(n) for n=0..22.

Formula

a(n)=-A103728(n+5, 7)=-(1 -(p(n+5)-1)*binomial(p(n+5)-1, 7))/p(n+5), with p(n):=A000040(n) (n-th prime).

a(n)= -(18108 - 26200*p(n+5) + 19901*p(n+5)^2 - 8729*p(n+5)^3 + 2282*p(n+5)^4 - 350*p(n+5)^5 + 29*p(n+5)^6 - p(n+5)^7)/7! = -sum(A103718(k, m)*p(n+5)^m, m=0..7)/7!.

Crossrefs

Sequence in context: A142915 A226473 A142366 * A232039 A301743 A178263

Adjacent sequences: A103731 A103732 A103733 * A103735 A103736 A103737

Keyword

nonn,easy

Author

Wolfdieter Lang, Feb 24 2005

Status

approved