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.

A250004 Numbers representable as x^y + x*y, where x>1, y>1 are integers (without multiplicity).

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%I A250004 #16 Feb 03 2015 17:16:07
%S A250004 8,14,15,24,35,36,42,48,63,76,80,93,99,120,140,142,143,168,195,224,
%T A250004 234,255,258,272,288,323,360,364,399,440,483,528,530,536,575,624,645,
%U A250004 675,728,747,756,783,840,899,960,1023,1030,1044,1088,1155,1224,1295,1320,1364,1368
%N A250004 Numbers representable as x^y + x*y, where x>1, y>1 are integers (without multiplicity).
%C A250004 The sequence of numbers representable as x^y + x*y in two or more ways begins: 24, 76, 272, 1044, 2208, 4120, 16412. Example: 2208 = 46^2 + 46*2 = 3^7 + 3*7.
%C A250004 The subsequence of squares begins: 36, 1764.
%e A250004 a(2) = 14 = 2^3 + 2*3.
%e A250004 a(3) = 15 = 3^2 + 3*2.
%e A250004 a(22) = 255 = 15^2 + 15*2.
%o A250004 (PARI) isok(n) = {for (p=2, floor(log(n)/log(2)), for (k=2, sqrtnint(n, p), if (n == k^p + p*k, return (1)););); return (0);} \\ _Michel Marcus_, Jan 16 2015
%Y A250004 Cf. A253775.
%Y A250004 Cf. A024036 is a subsequence, except first 2 terms.
%K A250004 nonn
%O A250004 1,1
%A A250004 _Alex Ratushnyak_, Jan 14 2015