id:A033568 - OEIS Search Results

Search: id:A033568

Displaying 1-1 of 1 results found.

page 1

Second pentagonal numbers with odd index: (2*n-1)*(3*n-1).

+0
7

1, 2, 15, 40, 77, 126, 187, 260, 345, 442, 551, 672, 805, 950, 1107, 1276, 1457, 1650, 1855, 2072, 2301, 2542, 2795, 3060, 3337, 3626, 3927, 4240, 4565, 4902, 5251, 5612, 5985, 6370, 6767, 7176, 7597 (list; graph; listen)

	OFFSET	`0,2`
	FORMULA	`G.f.: A(x) = (1-x+12*x^2)/(1-x)^3.`
	CROSSREFS	`Cf. A005449, A049453, A033570.` `Sequence in context: A007217 A070009 A070170 this_sequence A032016 A001007 A152015` `Adjacent sequences: A033565 A033566 A033567 this_sequence A033569 A033570 A033571`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com).`

page 1

Search completed in 0.002 seconds

Last modified November 22 15:28 EST 2009. Contains 167310 sequences.

AT&T Labs Research