A078455 a(1) = 2. For n>1, a(n) = smallest m such that m == 0 (mod prime(n)), m + 1 == 0 (mod prime(n+1)) and m-1 == 0 (mod prime(n-1)).

2, 9, 55, 21, 792, 1937, 170, 4047, 115, 9454, 31930, 23902, 2665, 44978, 65189, 122483, 134992, 170983, 220028, 101104, 85556, 27887, 296725, 629141, 154327, 546208, 46865, 950588, 1043893, 1548891, 70739, 702946, 2389965, 1513988

Offset

1,1

Comments

A subsequence of the mean of three consecutive numbers divisible by three consecutive primes (A-number?).

Links

Table of n, a(n) for n=1..34.

Example

a(7) = 170. prime(7) = 17, prime(7-1) = 13, prime(7+1)=19 and 17 | 170, 19 | 171, 13 | 169 and 170 is the smallest such number.

Mathematica

(* First do <<NumberTheory`NumberTheoryFunctions` *) a[1]=2; a[n_] := ChineseRemainder[{1, 0, Prime[n+1]-1}, Prime/@Range[n-1, n+1]]

Crossrefs

Sequence in context: A001757 A267225 A377461 * A366177 A355281 A036074

Adjacent sequences: A078452 A078453 A078454 * A078456 A078457 A078458

Keyword

easy,nonn

Author

Amarnath Murthy, Dec 23 2002

Extensions

More terms from Jim Nastos, Feb 19 2003 and Dean Hickerson, Feb 23 2003

Status

approved