editing

approved

Sums of 5 or more consecutive nonnegative integers.

Ray Chandler, <a href="/A138593/b138593.txt">Table of n, a(n) for n = 1..10000</a>

approved

editing

_Vladimir Joseph Stephan Orlovsky (4vladimir(AT)gmail.com), _, May 13 2008

More terms from _Vladimir Joseph Stephan Orlovsky (4vladimir(AT)gmail.com), _, Mar 07 2010

Also: the numbers of the form s*k+A000217(k-1), s>=0, k>=5. Changing the lower limit to k from 5 to 2, 4 or 6 also defines A138591, A138592 and A138594. [From _R. J. Mathar (mathar(AT)strw.leidenuniv.nl), _, Jul 31 2008]

10, 15, 20, 21, 25, 27, 28, 30, 33, 35, 36, 39, 40, 42, 44, 45, 49, 50, 51, 52, 54, 55, 56, 57, 60, 63, 65, 66, 68, 69, 70, 72, 75, 76, 77, 78, 80, 81, 84, 85, 87, 88, 90, 91, 92, 93, 95, 98, 99, 100, 102, 104, 105, 108, 110, 111, 112, 114, 115, 116, 117, 119, 120, 121

nonn,new

nonn

More terms from Vladimir Orlovsky (4vladimir(AT)gmail.com), Mar 07 2010

Also: the numbers of the form s*k+A000217(k-1), s>=0, k>=5. Changing the lower limit to k from 5 to 2, 4 or 6 also defines A138591, A138592 and A138594. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 31 2008]

nonn,new

nonn

Sums of 5 or more consecutive integers.

10, 15, 20, 21, 25, 27, 28, 30, 33, 35, 36, 39, 40, 42, 44, 45, 49, 50, 51, 52, 54, 55, 56, 57, 60, 63, 65, 66, 68, 69, 70

1,1

0+1+2=3+4=10, 1+2+3+4+5=15, 2+3+4+5+6=20, 1+2+3+4+5+6=21,...

Array[r, 9]; k=0; For[i=0, i<=55, a=i*4+6; For[j=i+4, j<=66, a=a+j; k++; r[k]=a; j++ ]; i++ ]; q=Union[Array[r, k]]; StringTake[ToString[q], 123]

nonn

Vladimir Orlovsky (4vladimir(AT)gmail.com), May 13 2008

approved