Composite numbers k such that all the decimal concatenations ik and ikj (i, j = 1...9) are also composite.

A032737

Composite numbers k such that all the decimal concatenations ik and ikj (i, j = 1...9) are also composite.

Terms

    a(0) =5620a(1) =7358a(2) =13308a(3) =13332a(4) =13650a(5) =14612a(6) =26302a(7) =27971a(8) =28472a(9) =28838a(10) =29542a(11) =29650a(12) =31328a(13) =33027a(14) =33170a(15) =35914a(16) =35970a(17) =36186a(18) =39608a(19) =40078a(20) =41165a(21) =41528a(22) =42422a(23) =47172a(24) =47382a(25) =48046a(26) =48052a(27) =48454a(28) =50774a(29) =52735

External references