A089795 - OEIS

A089795

Smallest prime(k) such that prime(k)-prime(k-1) is equal to prime(k+n)-prime(k).

5, 37, 1009, 4327, 6197, 6947, 43391, 31469, 1324567, 678719, 6655531, 1895479, 6085103, 21500429, 93685619, 523000399, 20388727, 709208557

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OFFSET

1,1

COMMENTS

LINKS

EXAMPLE

a(4) = 4327, the previous prime is 4297, 4327-4297 = 30, the next four primes are 4337, 4339, 4349 and 4357. 4357-4327 = 30.

MATHEMATICA

f[n_] := Block[{k = n + 1}, While[ 2Prime[k] != Prime[k - 1] + Prime[k + n], k++ ]; Prime[k]]; Table[ f[n], {n, 18}]

PROG

(PARI) a(n)=local(k=1); if(n<1, 0, until(prime(k)-prime(k-1)==prime(k+n)-prime(k), k++); prime(k)) /* Michael Somos, Feb 01 2004 */

CROSSREFS

KEYWORD

nonn

AUTHOR

STATUS

approved