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 A082737 Triangle read by rows in which the first row contains a 1 and the n-th row contains n primes not included in the previous rows such that the sum of a row is a perfect square. 4

%I

%S 1,2,7,3,5,17,11,13,19,101,23,29,31,37,241,41,43,47,53,59,157,61,67,

%T 71,73,79,83,191,89,97,103,107,109,113,127,1019,131,137,139,149,151,

%U 163,167,173,311,179,181,193,197,199,211,223,227,229,277,233,239,251,257

%N Triangle read by rows in which the first row contains a 1 and the n-th row contains n primes not included in the previous rows such that the sum of a row is a perfect square.

%C Another rearrangement of primes and 1.

%e 1

%e 2 7

%e 3 5 17

%e 11 13 19 101

%e 23 29 31 37 241

%e ...

%p A082737 := proc(nmax) local a,n,r,i,rsum,c,j ; a := [1,2,7] ; n := 3 ; i := 1 ; while nops(a)< nmax do r := [] ; for c from 1 to n-1 do while ithprime(i) in a or ithprime(i) in r do i:= i+1 ; od ; r := [op(r),ithprime(i)] ; i:= i+1 ; od ; j := i+1 ; rsum := sum(op(k,r),k=1..nops(r)) ; while not issqr( rsum+ithprime(j)) do j := j+1 ; od ; r := [op(r),ithprime(j)] ; a := [op(a),op(r)] ; n := n+1 ; od ; RETURN(a) ; end: a := A082737(80) : for n from 1 to nops(a) do printf("%d,",op(n,a)) ; od ; # _R. J. Mathar_, Nov 12 2006

%Y Cf. A082738, A082739, A082740.

%K nonn,tabl

%O 1,2

%A _Amarnath Murthy_, Apr 14 2003

%E More terms from _R. J. Mathar_, Nov 12 2006

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Last modified September 16 23:53 EDT 2021. Contains 347477 sequences. (Running on oeis4.)