A249567 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A249567

a(1)=1; thereafter a(n) = smallest square m^2 such that m^2 minus (sum of all previous terms) is prime.

1, 4, 16, 64, 144, 576, 1296, 3600, 6084, 15876, 28224, 82944, 147456, 298116, 627264, 1218816, 2433600, 4928400, 9809424, 19607184, 39237696, 78535044, 158155776, 316057284, 633830976, 1265509476, 2532303684, 5062891716, 10128007044, 20260106244, 40519274436, 81043841124

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

OFFSET

1,2

LINKS

Robert Israel, Table of n, a(n) for n = 1..3310

EXAMPLE

16 - (1+4) = 11 (prime), 64 - (1+4+16) = 43 (prime).

MAPLE

A[1]:= 1: S:= 1:

for n from 2 to 100 do

m0:= ceil(sqrt(2+S));

if m0::odd then m0:= m0+1 fi;

for m from m0 by 2 do

if isprime(m^2 - S) then

A[n]:= m^2;

S:= S + A[n];

break

od:

seq(A[i], i=1..100); # Robert Israel, Nov 14 2016

MATHEMATICA

A249567 = {1}; n = 2; While[n < 10^5, If[n^2 - Total[A249567] > 0 && PrimeQ[n^2 - Total[A249567]], AppendTo[A249567, n^2]]; n++]; A249567 (* Ivan N. Ianakiev, Nov 03 2014 *)

CROSSREFS

Sequence in context: A328850 A330687 A027676 * A348906 A177398 A343200

Adjacent sequences: A249564 A249565 A249566 * A249568 A249569 A249570

KEYWORD

nonn

AUTHOR

Zak Seidov, Nov 01 2014

STATUS

approved