A239659 Sum of first n parts of the spiral described in A239660.

1, 4, 6, 8, 15, 18, 21, 33, 37, 41, 56, 61, 64, 69, 78, 87, 93, 99, 127, 134, 141, 153, 165, 173, 181, 189, 220, 229, 238, 277, 287, 297, 339, 350, 355, 360, 371, 389, 407, 419, 431, 491, 504, 509, 522, 543, 564, 578, 584, 590, 604, 660, 675, 690, 762, 778, 794, 857, 874, 881, 888, 905, 932, 959, 977, 989, 1007, 1098

Offset: 1

Author

Omar E. Pol, Mar 31 2014

Keywords

• nonn
• tabf

Comments

We can find the spiral on the terraces of the stepped pyramid described in A244050. - Omar E. Pol, Dec 07 2016

Examples

			If written as an irregular triangle in which row lengths is A237271 the sequence begins:
1;
4;
6, 8;
15;
18, 21;
33;
37, 41;
56;
61, 64, 69;
78, 87;
93, 99;
127;
134, 141;
153, 165;
173, 181, 189;
220;
229, 238;
277;
287, 297;
339;
350, 355, 360, 371;
389, 407;
419, 431;
491;
504, 509, 522;
...
Right border gives A024916.
		

Crossrefs

Partial sums of A237270.

Cf. A000203, A024916, A196020, A237593, A237271, A239660, A244050, A245092, A262626.