A065226 - OEIS

A065226

Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the decagonal numbers. The final elements of the rows form a(n).

%I #5 Aug 21 2023 22:01:41

%S 1,2,5,9,4,10,17,25,7,17,28,40,1,15,30,46,63,81,15,35,56,78,101,125,

%T 24,50,77,105,134,164,20,52,85,119,154,190,227,33,72,112,153,195,238,

%U 282,30,76,123,171,220,270,321,3,56,110,165,221,278,336,395,4,65,127,190

%N Fill a triangular array by rows by writing numbers 1 up to b(0), 1 up to b(1), etc., where b(n) are the decagonal numbers. The final elements of the rows form a(n).

%Y Cf. A001107, A064766, A064865, A065221-A065225, A065227-A065234.

%K easy,nonn

%O 0,2

%A _Floor van Lamoen_, Oct 22 2001