A075455 - OEIS

A075455

Prime averages of two successive perfect powers (A001597(k) + A001597(k+1))/2.

2203, 77983, 90863, 185477, 371087, 388573, 613607, 912349, 1293899, 1600919, 2146457, 30661333, 35608189, 48823147, 81190429, 105823093, 122753857, 204341747, 338602837, 368601707, 374788121, 426958673, 498675409, 586371239, 656232799, 665360321, 674509487, 693132527

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..28.

EXAMPLE

2203 = (A001597(61)+A001597(62))/2 = (2197+2209)/2.

MATHEMATICA

a = Select[Range[2, 50000000], GCD @@ (Transpose[FactorInteger[ # ]][[2]]) > 1 &]; sizea = Length[a]; (a[[Select[Range[sizea - 1], PrimeQ[(a[[ # ]] + a[[ # + 1]])/2] &]]] + a[[Select[Range[sizea - 1], PrimeQ[(a[[ # ]] + a[[ # + 1]])/2] &] + 1]])/2 (* Tanya Khovanova, Sep 15 2007 *)

CROSSREFS

Cf. A001597.

Sequence in context: A019297 A044989 A202894 * A233444 A125015 A348743

Adjacent sequences: A075452 A075453 A075454 * A075456 A075457 A075458

KEYWORD

easy,nonn

AUTHOR

Zak Seidov, Oct 11 2002

EXTENSIONS

More terms from Tanya Khovanova, Sep 15 2007

More terms from Amiram Eldar, Feb 18 2022

STATUS

approved