1,1

Basis for sequence is shortest arithmetic series with initial term 1 and difference n that sums to a perfect square.

1+(1+1*n)+(1+2*n)+...+(1+A100254(n)*n)= 1+(1+1*n)+(1+2*n)+...+A100253(n)=a(n)^2=A100252(n)

a(3)=99 since 1 + 4 + 7 +...+ (1+80*3)= 99^2 = 9801 and no other arithmetic series with initial term 1, difference 3 and fewer terms sums to a perfect square.

Adjacent sequences: A100248 A100249 A100250 this_sequence A100252 A100253 A100254

Sequence in context: A084249 A096039 A038256 this_sequence A020339 A154738 A100125

nonn

Charlie Marion (charliemath(AT)optonline.net), Nov 21 2004