

A195038


41 times triangular numbers.


1



0, 41, 123, 246, 410, 615, 861, 1148, 1476, 1845, 2255, 2706, 3198, 3731, 4305, 4920, 5576, 6273, 7011, 7790, 8610, 9471, 10373, 11316, 12300, 13325, 14391, 15498, 16646, 17835, 19065, 20336, 21648, 23001, 24395, 25830, 27306, 28823, 30381, 31980
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OFFSET

0,2


COMMENTS

Related to the primitive Pythagorean triple [21, 20, 29].
Sequence found by reading the line from 0, in the direction 0, 41,..., and the same line from 0, in the direction 0, 123,..., in the Pythagorean spiral whose edges have length A195033 and whose vertices are the numbers A195034. This is the main diagonal of the square spiral.


LINKS



FORMULA

a(n) = (41*n^2 + 41*n)/2 = 41*n*(n+1)/2 = 41*A000217(n).


MATHEMATICA

41*Accumulate[Range[0, 40]] (* or *) LinearRecurrence[{3, 3, 1}, {0, 41, 123}, 40] (* Harvey P. Dale, Nov 20 2015 *)


PROG



CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



