cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A330553 Erroneous version of A275649.

Original entry on oeis.org

2, 14, 112, 997, 8982, 82305, 746092, 7159654, 67581778, 641696858, 6112456540, 58649349743
Offset: 1

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Author

Keywords

Comments

Included in accordance with OEIS policy of recording published but incorrect sequences to serve as pointers to the correct versions.

Crossrefs

Cf. A275649.

A164775 a(n) is the number of positive integers <= 10^n that can be expressed as a sum of two squares.

Original entry on oeis.org

7, 43, 330, 2749, 24028, 216341, 1985459, 18457847, 173229058, 1637624156, 15570512744, 148736628858, 1426306930865, 13722217893214, 132387263219058, 1280309691127436
Offset: 1

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Author

Eric W. Weisstein, Aug 26 2009

Keywords

Examples

			a(1)=7 since 1 = 0^2 + 1^2, 2 = 1^2 + 1^2, 4 = 0^2 + 2^2, 5 = 1^2 + 2^2, 8 = 2^2 + 2^2, 9 = 0^2 + 3^2, 10 = 1^2 + 3^3.
		

Crossrefs

Formula

a(n) = A180416(n) + ceiling(sqrt(10^n)). - Hiroaki Yamanouchi, Jul 14 2014

Extensions

Offset changed from 0 to 1 by Robert G. Wilson v, Aug 29 2009
a(9) from Eric W. Weisstein, Aug 29 2009
a(10) from Donovan Johnson, Sep 16 2009
a(11)-a(12) from Ant King, May 02 2010
a(11)-a(12) corrected and a(13)-a(16) added by Hiroaki Yamanouchi, Jul 14 2014

A275650 Number of positive integers k less than 10^n such that k is a sum of two squares and k/2 is an even power.

Original entry on oeis.org

4, 28, 214, 1803, 15830, 142844, 1313047, 12220699, 114790260, 1085885280, 10330026070, 98719755796, 947012920362, 9113815047794, 87950106960771, 850754904051968
Offset: 1

Views

Author

Felix Fröhlich, Aug 04 2016

Keywords

Comments

This sequence gives the values of the counting function V(x), whose values are given in table 3 on page 359 of Shiu, 1986.

Crossrefs

Cf. A164775: W(x), A275649: U(x).

Extensions

a(12) corrected and a(13)-a(16) added by Hiroaki Yamanouchi, Dec 25 2016
Showing 1-3 of 3 results.