A076769 Integers not expressible as the sum of a positive triangular number and a square.

8, 9, 13, 18, 20, 23, 27, 33, 34, 38, 41, 43, 47, 48, 58, 60, 62, 63, 68, 69, 73, 76, 83, 86, 88, 89, 90, 93, 97, 98, 99, 108, 111, 112, 113, 118, 123, 125, 132, 133, 134, 135, 138, 139, 143, 144, 146, 148, 151, 158, 160, 163, 164, 167, 168, 173, 174, 177, 181, 182

Offset

1,1

Links

Table of n, a(n) for n=1..60.

Prog

(PARI) isok(n)={for(k=1, sqrtint(2*n), if(issquare(n-binomial(k+1, 2)), return(0))); 1} \\ Andrew Howroyd, Sep 18 2024

Crossrefs

Cf. A000217, A000290, A014134.

Sequence in context: A079525 A083131 A101591 * A105741 A286475 A334915

Adjacent sequences: A076766 A076767 A076768 * A076770 A076771 A076772

Keyword

nonn

Author

Jason Earls, Nov 14 2002

Extensions

Name clarified and offset changed by Andrew Howroyd, Sep 18 2024

Status

approved