A076430 Sum of squares of numbers that cannot be written as t*p(n) + u*p(n+1) for nonnegative integers t,u, where p(n) is the n-th prime.

1, 70, 1610, 22715, 170170, 675376, 2224824, 5696295, 21057190, 52798270, 111385170, 261955560, 414410780, 628310711, 1187225546, 2369546790, 3631067090, 5339542890, 8459444455, 10969197540, 15154637940, 22349763995

Offset

1,2

References

Fred. Schuh, Vragen betreffende een onbepaalde vergelijking, Nieuw Tijdschrift voor Wiskunde, 52 (1964-1965) 193-198.

Links

Table of n, a(n) for n=1..22.

Formula

a(n) = p(n) * p(n+1) * (p(n)-1) * (p(n+1)-1) * (p(n)*p(n+1)-p(n)-p(n+1)) / 12.

Maple

seq(ithprime(n)*ithprime(n+1)*(ithprime(n)-1)*(ithprime(n+1)-1)*(ithprime(n)*ithprime(n+1)-ithprime(n)-ithprime(n+1))/12, n=1..30);

Crossrefs

Cf. A076389, A076429.

Sequence in context: A298973 A278548 A107421 * A006296 A047835 A133312

Adjacent sequences: A076427 A076428 A076429 * A076431 A076432 A076433

Keyword

nonn

Author

Floor van Lamoen, Oct 10 2002

Status

approved